selinux: introduce an initial SID for early boot processes

Currently, SELinux doesn't allow distinguishing between kernel threads
and userspace processes that are started before the policy is first
loaded - both get the label corresponding to the kernel SID. The only
way a process that persists from early boot can get a meaningful label
is by doing a voluntary dyntransition or re-executing itself.

Reusing the kernel label for userspace processes is problematic for
several reasons:
1. The kernel is considered to be a privileged domain and generally
needs to have a wide range of permissions allowed to work correctly,
which prevents the policy writer from effectively hardening against
early boot processes that might remain running unintentionally after
the policy is loaded (they represent a potential extra attack surface
that should be mitigated).
2. Despite the kernel being treated as a privileged domain, the policy
writer may want to impose certain special limitations on kernel
threads that may conflict with the requirements of intentional early
boot processes. For example, it is a good hardening practice to limit
what executables the kernel can execute as usermode helpers and to
confine the resulting usermode helper processes. However, a
(legitimate) process surviving from early boot may need to execute a
different set of executables.
3. As currently implemented, overlayfs remembers the security context of
the process that created an overlayfs mount and uses it to bound
subsequent operations on files using this context. If an overlayfs
mount is created before the SELinux policy is loaded, these "mounter"
checks are made against the kernel context, which may clash with
restrictions on the kernel domain (see 2.).

To resolve this, introduce a new initial SID (reusing the slot of the
former "init" initial SID) that will be assigned to any userspace
process started before the policy is first loaded. This is easy to do,
as we can simply label any process that goes through the
bprm_creds_for_exec LSM hook with the new init-SID instead of
propagating the kernel SID from the parent.

To provide backwards compatibility for existing policies that are
unaware of this new semantic of the "init" initial SID, introduce a new
policy capability "userspace_initial_context" and set the "init" SID to
the same context as the "kernel" SID unless this capability is set by
the policy.

Another small backwards compatibility measure is needed in
security_sid_to_context_core() for before the initial SELinux policy
load - see the code comment for explanation.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: edited comments based on feedback/discussion]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: make left shifts well defined

The loops upper bound represent the number of permissions used (for the
current class or in general). The limit for this is 32, thus we might
left shift of one less, 31. Shifting a base of 1 results in undefined
behavior; use (u32)1 as base.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: update type for number of class permissions in services code

Security classes have only up to 32 permissions, hence using an u16 is
sufficient (while improving padding in struct selinux_mapping).

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: avoid implicit conversions in services code

Use u32 as the output parameter type in security_get_classes() and
security_get_permissions(), based on the type of the symtab nprim
member.

Declare the read-only class string parameter of
security_get_permissions() const.

Avoid several implicit conversions by using the identical type for the
destination.

Use the type identical to the source for local variables.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: cleanup extra whitespace in subject]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: update my email address

Update my email address; MAINTAINERS was updated some time ago.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: drop avtab_search()

avtab_search() shares the same logic with avtab_search_node(), except
that it returns, if found, a pointer to the struct avtab_node member
datum instead of the node itself. Since the member is an embedded
struct, and not a pointer, the returned value of avtab_search() and
avtab_search_node() will always in unison either be NULL or non-NULL.

Drop avtab_search() and replace its calls by avtab_search_node() to
deduplicate logic and adopt the only caller caring for the type of
the returned value accordingly.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: use consistent type for AV rule specifier

The specifier for avtab keys is always supplied with a type of u16,
either as a macro to security_compute_sid() or the member specified of
the struct avtab_key.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: small cleanups in selinux_audit_rule_init()

A few small tweaks to selinux_audit_rule_init():

- Adjust how we use the @rc variable so we are not doing any extra
work in the common/success case.

- Related to the above, rework the 'out' jump label so that the
success and error paths are different, simplifying both.

- Cleanup some of the vertical whitespace while we are making the
other changes.

Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: adjust typos in comments

Found by codespell(1)

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: stop passing selinux_state pointers and their offspring

Linus observed that the pervasive passing of selinux_state pointers
introduced by me in commit aa8e712cee93 ("selinux: wrap global selinux
state") adds overhead and complexity without providing any
benefit. The original idea was to pave the way for SELinux namespaces
but those have not yet been implemented and there isn't currently
a concrete plan to do so. Remove the passing of the selinux_state
pointers, reverting to direct use of the single global selinux_state,
and likewise remove passing of child pointers like the selinux_avc.
The selinux_policy pointer remains as it is needed for atomic switching
of policies.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202303101057.mZ3Gv5fK-lkp@intel.com/
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: remove the sidtab context conversion indirect calls

The sidtab conversion code has support for multiple context
conversion routines through the use of function pointers and
indirect calls. However, the reality is that all current users rely
on the same conversion routine: convert_context(). This patch does
away with this extra complexity and replaces the indirect calls
with direct function calls; allowing us to remove a layer of
obfuscation and create cleaner, more maintainable code.

Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context()

The following warning was triggered on a hardware environment:

SELinux: Converting 162 SID table entries...
BUG: sleeping function called from invalid context at
__might_sleep+0x60/0x74 0x0
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 5943, name: tar
CPU: 7 PID: 5943 Comm: tar Tainted: P O 5.10.0 #1
Call trace:
dump_backtrace+0x0/0x1c8
show_stack+0x18/0x28
dump_stack+0xe8/0x15c
___might_sleep+0x168/0x17c
__might_sleep+0x60/0x74
__kmalloc_track_caller+0xa0/0x7dc
kstrdup+0x54/0xac
convert_context+0x48/0x2e4
sidtab_context_to_sid+0x1c4/0x36c
security_context_to_sid_core+0x168/0x238
security_context_to_sid_default+0x14/0x24
inode_doinit_use_xattr+0x164/0x1e4
inode_doinit_with_dentry+0x1c0/0x488
selinux_d_instantiate+0x20/0x34
security_d_instantiate+0x70/0xbc
d_splice_alias+0x4c/0x3c0
ext4_lookup+0x1d8/0x200 [ext4]
__lookup_slow+0x12c/0x1e4
walk_component+0x100/0x200
path_lookupat+0x88/0x118
filename_lookup+0x98/0x130
user_path_at_empty+0x48/0x60
vfs_statx+0x84/0x140
vfs_fstatat+0x20/0x30
__se_sys_newfstatat+0x30/0x74
__arm64_sys_newfstatat+0x1c/0x2c
el0_svc_common.constprop.0+0x100/0x184
do_el0_svc+0x1c/0x2c
el0_svc+0x20/0x34
el0_sync_handler+0x80/0x17c
el0_sync+0x13c/0x140
SELinux: Context system_u:object_r:pssp_rsyslog_log_t:s0:c0 is
not valid (left unmapped).

It was found that within a critical section of spin_lock_irqsave in
sidtab_context_to_sid(), convert_context() (hooked by
sidtab_convert_params.func) might cause the process to sleep via
allocating memory with GFP_KERNEL, which is problematic.

As Ondrej pointed out [1], convert_context()/sidtab_convert_params.func
has another caller sidtab_convert_tree(), which is okay with GFP_KERNEL.
Therefore, fix this problem by adding a gfp_t argument for
convert_context()/sidtab_convert_params.func and pass GFP_KERNEL/_ATOMIC
properly in individual callers.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20221018120111.1474581-1-gongruiqi1@huawei.com/ [1]
Reported-by: Tan Ninghao <tanninghao1@huawei.com>
Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance")
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: wrap long BUG() output lines, tweak subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix memleak in security_read_state_kernel()

In this function, it directly returns the result of __security_read_policy
without freeing the allocated memory in *data, cause memory leak issue,
so free the memory if __security_read_policy failed.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: declare data arrays const

The arrays for the policy capability names, the initial sid identifiers
and the class and permission names are not changed at runtime. Declare
them const to avoid accidental modification.

Do not override the classmap and the initial sid list in the build time
script genheaders.

Check flose(3) is successful in genheaders.c, otherwise the written data
might be corrupted or incomplete.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: manual merge due to fuzz, minor style tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix indentation level of mls_ops block

Add one level of indentation to the code block of the label mls_ops in
constraint_expr_eval(), to adjust the trailing break; to the parent
case: branch.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Remove redundant assignments

Get rid of redundant assignments which end up in values not being
read either because they are overwritten or the function ends.

Reported by clang-tidy [deadcode.DeadStores]

Signed-off-by: Michal Orzel <michalorzel.eng@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: drop return statement at end of void functions

Those return statements at the end of a void function are redundant.

Reported by clang-tidy [readability-redundant-control-flow]

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: drop cast to same type

Both the lvalue scontextp and rvalue scontext are of the type char*.
Drop the redundant explicit cast not needed since commit 9a59daa03df7
("SELinux: fix sleeping allocation in security_context_to_sid"), where
the type of scontext changed from const char* to char*.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: declare path parameters of _genfs_sid const

The path parameter is only read from in security_genfs_sid(),
selinux_policy_genfs_sid() and __security_genfs_sid(). Since a string
literal is passed as argument, declare the parameter const.
Also align the parameter names in the declaration and definition.

Reported by clang [-Wwrite-strings]:

security/selinux/hooks.c:553:60: error: passing 'const char [2]'
to parameter of type 'char *' discards qualifiers
[-Wincompatible-pointer-types-discards-qualifiers]
rc = security_genfs_sid(&selinux_state, ... , /,
^~~
./security/selinux/include/security.h:389:36: note: passing
argument to parameter 'name' here
const char *fstype, char *name, u16 sclass,
^

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: wrapped description]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix all of the W=1 build warnings

There were a number of places in the code where the function
definition did not match the associated comment block as well
at least one file where the appropriate header files were not
included (missing function declaration/prototype); this patch
fixes all of these issue such that building the SELinux code
with "W=1" is now warning free.

% make W=1 security/selinux/

Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix race condition when computing ocontext SIDs

Current code contains a lot of racy patterns when converting an
ocontext's context structure to an SID. This is being done in a "lazy"
fashion, such that the SID is looked up in the SID table only when it's
first needed and then cached in the "sid" field of the ocontext
structure. However, this is done without any locking or memory barriers
and is thus unsafe.

Between commits 24ed7fdae669 ("selinux: use separate table for initial
SID lookup") and 66f8e2f03c02 ("selinux: sidtab reverse lookup hash
table"), this race condition lead to an actual observable bug, because a
pointer to the shared sid field was passed directly to
sidtab_context_to_sid(), which was using this location to also store an
intermediate value, which could have been read by other threads and
interpreted as an SID. In practice this caused e.g. new mounts to get a
wrong (seemingly random) filesystem context, leading to strange denials.
This bug has been spotted in the wild at least twice, see [1] and [2].

Fix the race condition by making all the racy functions use a common
helper that ensures the ocontext::sid accesses are made safely using the
appropriate SMP constructs.

Note that security_netif_sid() was populating the sid field of both
contexts stored in the ocontext, but only the first one was actually
used. The SELinux wiki's documentation on the "netifcon" policy
statement [3] suggests that using only the first context is intentional.
I kept only the handling of the first context here, as there is really
no point in doing the SID lookup for the unused one.

I wasn't able to reproduce the bug mentioned above on any kernel that
includes commit 66f8e2f03c02, even though it has been reported that the
issue occurs with that commit, too, just less frequently. Thus, I wasn't
able to verify that this patch fixes the issue, but it makes sense to
avoid the race condition regardless.

[1] https://github.com/containers/container-selinux/issues/89
[2] https://lists.fedoraproject.org/archives/list/selinux@lists.fedoraproject.org/thread/6DMTAMHIOAOEMUAVTULJD45JZU7IBAFM/
[3] https://selinuxproject.org/page/NetworkStatements#netifcon

Cc: stable@vger.kernel.org
Cc: Xinjie Zheng <xinjie@google.com>
Reported-by: Sujithra Periasamy <sujithra@google.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: return early for possible NULL audit buffers

audit_log_start() may return NULL in below cases:

- when audit is not initialized.
- when audit backlog limit exceeds.

After the call to audit_log_start() is made and then possible NULL audit
buffer argument is passed to audit_log_*() functions,
audit_log_*() functions return immediately in case of a NULL audit buffer
argument.

But it is optimal to return early when audit_log_start() returns NULL,
because it is not necessary for audit_log_*() functions to be called with
NULL audit buffer argument.

So add exception handling for possible NULL audit buffers where
return value can be handled from callers.

Signed-off-by: Austin Kim <austin.kim@lge.com>
[PM: tweak subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Fix kernel-doc

Fix function name and add comment for parameter state in ss/services.c
kernel-doc to remove some warnings found by running make W=1 LLVM=1.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Remove redundant assignment to rc

Variable rc is set to '-EINVAL' but this value is never read as
it is overwritten or not used later on, hence it is a redundant
assignment and can be removed.

Cleans up the following clang-analyzer warning:

security/selinux/ss/services.c:2103:3: warning: Value stored to 'rc' is
never read [clang-analyzer-deadcode.DeadStores].

security/selinux/ss/services.c:2079:2: warning: Value stored to 'rc' is
never read [clang-analyzer-deadcode.DeadStores].

security/selinux/ss/services.c:2071:2: warning: Value stored to 'rc' is
never read [clang-analyzer-deadcode.DeadStores].

security/selinux/ss/services.c:2062:2: warning: Value stored to 'rc' is
never read [clang-analyzer-deadcode.DeadStores].

security/selinux/ss/policydb.c:2592:3: warning: Value stored to 'rc' is
never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

LSM: Infrastructure management of the superblock

Move management of the superblock->sb_security blob out of the
individual security modules and into the security infrastructure.
Instead of allocating the blobs from within the modules, the modules
tell the infrastructure how much space is required, and the space is
allocated there.

Cc: John Johansen <john.johansen@canonical.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-6-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>

selinux: measure state and policy capabilities

SELinux stores the configuration state and the policy capabilities
in kernel memory. Changes to this data at runtime would have an impact
on the security guarantees provided by SELinux. Measuring this data
through IMA subsystem provides a tamper-resistant way for
an attestation service to remotely validate it at runtime.

Measure the configuration state and policy capabilities by calling
the IMA hook ima_measure_critical_data().

To enable SELinux data measurement, the following steps are required:

1, Add "ima_policy=critical_data" to the kernel command line arguments
to enable measuring SELinux data at boot time.
For example,
BOOT_IMAGE=/boot/vmlinuz-5.11.0-rc3+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data

2, Add the following rule to /etc/ima/ima-policy
measure func=CRITICAL_DATA label=selinux

Sample measurement of SELinux state and policy capabilities:

10 2122...65d8 ima-buf sha256:13c2...1292 selinux-state 696e...303b

Execute the following command to extract the measured data
from the IMA's runtime measurements list:

grep "selinux-state" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6 | xxd -r -p

The output should be a list of key-value pairs. For example,
initialized=1;enforcing=0;checkreqprot=1;network_peer_controls=1;open_perms=1;extended_socket_class=1;always_check_network=0;cgroup_seclabel=1;nnp_nosuid_transition=1;genfs_seclabel_symlinks=0;

To verify the measurement is consistent with the current SELinux state
reported on the system, compare the integer values in the following
files with those set in the IMA measurement (using the following commands):

- cat /sys/fs/selinux/enforce
- cat /sys/fs/selinux/checkreqprot
- cat /sys/fs/selinux/policy_capabilities/[capability_file]

Note that the actual verification would be against an expected state
and done on a separate system (likely an attestation server) requiring
"initialized=1;enforcing=1;checkreqprot=0;"
for a secure state and then whatever policy capabilities are actually
set in the expected policy (which can be extracted from the policy
itself via seinfo, for example).

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix race between old and new sidtab

Since commit 1b8b31a2e612 ("selinux: convert policy read-write lock to
RCU"), there is a small window during policy load where the new policy
pointer has already been installed, but some threads may still be
holding the old policy pointer in their read-side RCU critical sections.
This means that there may be conflicting attempts to add a new SID entry
to both tables via sidtab_context_to_sid().

See also (and the rest of the thread):
https://lore.kernel.org/selinux/CAFqZXNvfux46_f8gnvVvRYMKoes24nwm2n3sPbMjrB8vKTW00g@mail.gmail.com/

Fix this by installing the new policy pointer under the old sidtab's
spinlock along with marking the old sidtab as "frozen". Then, if an
attempt to add new entry to a "frozen" sidtab is detected, make
sidtab_context_to_sid() return -ESTALE to indicate that a new policy
has been installed and that the caller will have to abort the policy
transaction and try again after re-taking the policy pointer (which is
guaranteed to be a newer policy). This requires adding a retry-on-ESTALE
logic to all callers of sidtab_context_to_sid(), but fortunately these
are easy to determine and aren't that many.

This seems to be the simplest solution for this problem, even if it
looks somewhat ugly. Note that other places in the kernel (e.g.
do_mknodat() in fs/namei.c) use similar stale-retry patterns, so I think
it's reasonable.

Cc: stable@vger.kernel.org
Fixes: 1b8b31a2e612 ("selinux: convert policy read-write lock to RCU")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix variable scope issue in live sidtab conversion

Commit 02a52c5c8c3b ("selinux: move policy commit after updating
selinuxfs") moved the selinux_policy_commit() call out of
security_load_policy() into sel_write_load(), which caused a subtle yet
rather serious bug.

The problem is that security_load_policy() passes a reference to the
convert_params local variable to sidtab_convert(), which stores it in
the sidtab, where it may be accessed until the policy is swapped over
and RCU synchronized. Before 02a52c5c8c3b, selinux_policy_commit() was
called directly from security_load_policy(), so the convert_params
pointer remained valid all the way until the old sidtab was destroyed,
but now that's no longer the case and calls to sidtab_context_to_sid()
on the old sidtab after security_load_policy() returns may cause invalid
memory accesses.

This can be easily triggered using the stress test from commit
ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve
performance"):
```
function rand_cat() {
echo $(( $RANDOM % 1024 ))
}

function do_work() {
while true; do
echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \
>/sys/fs/selinux/context 2>/dev/null || true
done
}

do_work >/dev/null &
do_work >/dev/null &
do_work >/dev/null &

while load_policy; do echo -n .; sleep 0.1; done

kill %1
kill %2
kill %3
```

Fix this by allocating the temporary sidtab convert structures
dynamically and passing them among the
selinux_policy_{load,cancel,commit} functions.

Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs")
Cc: stable@vger.kernel.org
Tested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: merge fuzz in security.h and services.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: include a consumer of the new IMA critical data hook

SELinux stores the active policy in memory, so the changes to this data
at runtime would have an impact on the security guarantees provided
by SELinux. Measuring in-memory SELinux policy through IMA subsystem
provides a secure way for the attestation service to remotely validate
the policy contents at runtime.

Measure the hash of the loaded policy by calling the IMA hook
ima_measure_critical_data(). Since the size of the loaded policy
can be large (several MB), measure the hash of the policy instead of
the entire policy to avoid bloating the IMA log entry.

To enable SELinux data measurement, the following steps are required:

1, Add "ima_policy=critical_data" to the kernel command line arguments
to enable measuring SELinux data at boot time.
For example,
BOOT_IMAGE=/boot/vmlinuz-5.10.0-rc1+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data

2, Add the following rule to /etc/ima/ima-policy
measure func=CRITICAL_DATA label=selinux

Sample measurement of the hash of SELinux policy:

To verify the measured data with the current SELinux policy run
the following commands and verify the output hash values match.

sha256sum /sys/fs/selinux/policy | cut -d' ' -f 1

grep "selinux-policy-hash" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6

Note that the actual verification of SELinux policy would require loading
the expected policy into an identical kernel on a pristine/known-safe
system and run the sha256sum /sys/kernel/selinux/policy there to get
the expected hash.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

selinux: drop the unnecessary aurule_callback variable

Its value is actually not changed anywhere, so it can be substituted for
a direct call to audit_update_lsm_rules().

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: allow dontauditx and auditallowx rules to take effect without allowx

This allows for dontauditing very specific ioctls e.g. TCGETS without
dontauditing every ioctl or granting additional permissions.

Now either an allowx, dontauditx or auditallowx rules enables checking
for extended permissions.

Signed-off-by: Jonathan Hettwer <j2468h@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: access policycaps with READ_ONCE/WRITE_ONCE

Use READ_ONCE/WRITE_ONCE for all accesses to the
selinux_state.policycaps booleans to prevent compiler
mischief.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: simplify away security_policydb_len()

Remove the security_policydb_len() calls from sel_open_policy() and
instead update the inode size from the size returned from
security_read_policy().

Since after this change security_policydb_len() is only called from
security_load_policy(), remove it entirely and just open-code it there.

Also, since security_load_policy() is always called with policy_mutex
held, make it dereference the policy pointer directly and drop the
unnecessary RCU locking.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: move policy mutex to selinux_state, use in lockdep checks

Move the mutex used to synchronize policy changes (reloads and setting
of booleans) from selinux_fs_info to selinux_state and use it in
lockdep checks for rcu_dereference_protected() calls in the security
server functions. This makes the dependency on the mutex explicit
in the code rather than relying on comments.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix error handling bugs in security_load_policy()

There are a few bugs in the error handling for security_load_policy().

1) If the newpolicy->sidtab allocation fails then it leads to a NULL
dereference. Also the error code was not set to -ENOMEM on that
path.
2) If policydb_read() failed then we call policydb_destroy() twice
which meands we call kvfree(p->sym_val_to_name[i]) twice.
3) If policydb_load_isids() failed then we call sidtab_destroy() twice
and that results in a double free in the sidtab_destroy_tree()
function because entry.ptr_inner and entry.ptr_leaf are not set to
NULL.

One thing that makes this code nice to deal with is that none of the
functions return partially allocated data. In other words, the
policydb_read() either allocates everything successfully or it frees
all the data it allocates. It never returns a mix of allocated and
not allocated data.

I re-wrote this to only free the successfully allocated data which
avoids the double frees. I also re-ordered selinux_policy_free() so
it's in the reverse order of the allocation function.

Fixes: c7c556f1e81b ("selinux: refactor changing booleans")
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[PM: partially merged by hand due to merge fuzz]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: convert policy read-write lock to RCU

Convert the policy read-write lock to RCU. This is significantly
simplified by the earlier work to encapsulate the policy data
structures and refactor the policy load and boolean setting logic.
Move the latest_granting sequence number into the selinux_policy
structure so that it can be updated atomically with the policy.
Since removing the policy rwlock and moving latest_granting reduces
the selinux_ss structure to nothing more than a wrapper around the
selinux_policy pointer, get rid of the extra layer of indirection.

At present this change merely passes a hardcoded 1 to
rcu_dereference_check() in the cases where we know we do not need to
take rcu_read_lock(), with the preceding comment explaining why.
Alternatively we could pass fsi->mutex down from selinuxfs and
apply a lockdep check on it instead.

Based in part on earlier attempts to convert the policy rwlock
to RCU by Kaigai Kohei [1] and by Peter Enderborg [2].

[1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/
[2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: avoid dereferencing the policy prior to initialization

Certain SELinux security server functions (e.g. security_port_sid,
called during bind) were not explicitly testing to see if SELinux
has been initialized (i.e. initial policy loaded) and handling
the no-policy-loaded case. In the past this happened to work
because the policydb was statically allocated and could always
be accessed, but with the recent encapsulation of policy state
and conversion to dynamic allocation, we can no longer access
the policy state prior to initialization. Add a test of
!selinux_initialized(state) to all of the exported functions that
were missing them and handle appropriately.

Fixes: 461698026ffa ("selinux: encapsulate policy state, refactor policy load")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix allocation failure check on newpolicy->sidtab

The allocation check of newpolicy->sidtab is null checking if
newpolicy is null and not newpolicy->sidtab. Fix this.

Addresses-Coverity: ("Logically dead code")
Fixes: c7c556f1e81b ("selinux: refactor changing booleans")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: refactor changing booleans

Refactor the logic for changing SELinux policy booleans in a similar
manner to the refactoring of policy load, thereby reducing the
size of the critical section when the policy write-lock is held
and making it easier to convert the policy rwlock to RCU in the
future. Instead of directly modifying the policydb in place, modify
a copy and then swap it into place through a single pointer update.
Only fully copy the portions of the policydb that are affected by
boolean changes to avoid the full cost of a deep policydb copy.
Introduce another level of indirection for the sidtab since changing
booleans does not require updating the sidtab, unlike policy load.
While we are here, create a common helper for notifying
other kernel components and userspace of a policy change and call it
from both security_set_bools() and selinux_policy_commit().

Based on an old (2004) patch by Kaigai Kohei [1] to convert the policy
rwlock to RCU that was deferred at the time since it did not
significantly improve performance and introduced complexity. Peter
Enderborg later submitted a patch series to convert to RCU [2] that
would have made changing booleans a much more expensive operation
by requiring a full policydb_write();policydb_read(); sequence to
deep copy the entire policydb and also had concerns regarding
atomic allocations.

This change is now simplified by the earlier work to encapsulate
policy state in the selinux_policy struct and to refactor
policy load. After this change, the last major obstacle to
converting the policy rwlock to RCU is likely the sidtab live
convert support.

[1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/
[2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: move policy commit after updating selinuxfs

With the refactoring of the policy load logic in the security
server from the previous change, it is now possible to split out
the committing of the new policy from security_load_policy() and
perform it only after successful updating of selinuxfs. Change
security_load_policy() to return the newly populated policy
data structures to the caller, export selinux_policy_commit()
for external callers, and introduce selinux_policy_cancel() to
provide a way to cancel the policy load in the event of an error
during updating of the selinuxfs directory tree. Further, rework
the interfaces used by selinuxfs to get information from the policy
when creating the new directory tree to take and act upon the
new policy data structure rather than the current/active policy.
Update selinuxfs to use these updated and new interfaces. While
we are here, stop re-creating the policy_capabilities directory
on each policy load since it does not depend on the policy, and
stop trying to create the booleans and classes directories during
the initial creation of selinuxfs since no information is available
until first policy load.

After this change, a failure while updating the booleans and class
directories will cause the entire policy load to be canceled, leaving
the original policy intact, and policy load notifications to userspace
will only happen after a successful completion of updating those
directories. This does not (yet) provide full atomicity with respect
to the updating of the directory trees themselves.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: encapsulate policy state, refactor policy load

Encapsulate the policy state in its own structure (struct
selinux_policy) that is separately allocated but referenced from the
selinux_ss structure. The policy state includes the SID table
(particularly the context structures), the policy database, and the
mapping between the kernel classes/permissions and the policy values.
Refactor the security server portion of the policy load logic to
cleanly separate loading of the new structures from committing the new
policy. Unify the initial policy load and reload code paths as much
as possible, avoiding duplicated code. Make sure we are taking the
policy read-lock prior to any dereferencing of the policy. Move the
copying of the policy capability booleans into the state structure
outside of the policy write-lock because they are separate from the
policy and are read outside of any policy lock; possibly they should
be using at least READ_ONCE/WRITE_ONCE or smp_load_acquire/store_release.

These changes simplify the policy loading logic, reduce the size of
the critical section while holding the policy write-lock, and should
facilitate future changes to e.g. refactor the entire policy reload
logic including the selinuxfs code to make the updating of the policy
and the selinuxfs directory tree atomic and/or to convert the policy
read-write lock to RCU.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

scripts/selinux,selinux: update mdp to enable policy capabilities

Presently mdp does not enable any SELinux policy capabilities
in the dummy policy it generates. Thus, policies derived from
it will by default lack various features commonly used in modern
policies such as open permission, extended socket classes, network
peer controls, etc. Split the policy capability definitions out into
their own headers so that we can include them into mdp without pulling in
other kernel headers and extend mdp generate policycap statements for the
policy capabilities known to the kernel. Policy authors may wish to
selectively remove some of these from the generated policy.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: prepare for inlining of hashtab functions

Refactor searching and inserting into hashtabs to pave the way for
converting hashtab_search() and hashtab_insert() to inline functions in
the next patch. This will avoid indirect calls and allow the compiler to
better optimize individual callers, leading to a significant performance
improvement.

In order to avoid the indirect calls, the key hashing and comparison
callbacks need to be extracted from the hashtab struct and passed
directly to hashtab_search()/_insert() by the callers so that the
callback address is always known at compile time. The kernel's
rhashtable library (<linux/rhashtable*.h>) does the same thing.

This of course makes the hashtab functions slightly easier to misuse by
passing a wrong callback set, but unfortunately there is no better way
to implement a hash table that is both generic and efficient in C. This
patch tries to somewhat mitigate this by only calling the hashtab
functions in the same file where the corresponding callbacks are
defined (wrapping them into more specialized functions as needed).

Note that this patch doesn't bring any benefit without also moving the
definitions of hashtab_search() and -_insert() to the header file, which
is done in a follow-up patch for easier review of the hashtab.c changes
in this patch.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: specialize symtab insert and search functions

This encapsulates symtab a little better and will help with further
refactoring later.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix double free

Clang's static analysis tool reports these double free memory errors.

security/selinux/ss/services.c:2987:4: warning: Attempt to free released memory [unix.Malloc]
kfree(bnames[i]);
^~~~~~~~~~~~~~~~
security/selinux/ss/services.c:2990:2: warning: Attempt to free released memory [unix.Malloc]
kfree(bvalues);
^~~~~~~~~~~~~~

So improve the security_get_bools error handling by freeing these variables
and setting their return pointers to NULL and the return len to 0

Cc: stable@vger.kernel.org
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: do not allocate hashtabs dynamically

It is simpler to allocate them statically in the corresponding
structure, avoiding unnecessary kmalloc() calls and pointer
dereferencing.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: manual merging required in policydb.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: move context hashing under sidtab

Now that context hash computation no longer depends on policydb, we can
simplify things by moving the context hashing completely under sidtab.
The hash is still cached in sidtab entries, but not for the in-flight
context structures.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: hash context structure directly

Always hashing the string representation is inefficient. Just hash the
contents of the structure directly (using jhash). If the context is
invalid (str & len are set), then hash the string as before, otherwise
hash the structured data.

Since the context hashing function is now faster (about 10 times), this
patch decreases the overhead of security_transition_sid(), which is
called from many hooks.

The jhash function seemed as a good choice, since it is used as the
default hashing algorithm in rhashtable.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Jeff Vander Stoep <jeffv@google.com>
Tested-by: Jeff Vander Stoep <jeffv@google.com>
[PM: fixed some spelling errors in the comments pointed out by JVS]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: store role transitions in a hash table

Currently, they are stored in a linked list, which adds significant
overhead to security_transition_sid(). On Fedora, with 428 role
transitions in policy, converting this list to a hash table cuts down
its run time by about 50%. This was measured by running 'stress-ng --msg
1 --msg-ops 100000' under perf with and without this patch.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix warning Comparison to bool

fix below warnings reported by coccicheck

security/selinux/ss/mls.c:539:39-43: WARNING: Comparison to bool
security/selinux/ss/services.c:1815:46-50: WARNING: Comparison to bool
security/selinux/ss/services.c:1827:46-50: WARNING: Comparison to bool

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: remove unused initial SIDs and improve handling

Remove initial SIDs that have never been used or are no longer used by
the kernel from its string table, which is also used to generate the
SECINITSID_* symbols referenced in code. Update the code to
gracefully handle the fact that these can now be NULL. Stop treating
it as an error if a policy defines additional initial SIDs unknown to
the kernel. Do not load unused initial SID contexts into the sidtab.
Fix the incorrect usage of the name from the ocontext in error
messages when loading initial SIDs since these are not presently
written to the kernel policy and are therefore always NULL.

After this change, it is possible to safely reclaim and reuse some of
the unused initial SIDs without compatibility issues. Specifically,
unused initial SIDs that were being assigned the same context as the
unlabeled initial SID in policies can be reclaimed and reused for
another purpose, with existing policies still treating them as having
the unlabeled context and future policies having the option of mapping
them to a more specific context. For example, this could have been
used when the infiniband labeling support was introduced to define
initial SIDs for the default pkey and endport SIDs similar to the
handling of port/netif/node SIDs rather than always using
SECINITSID_UNLABELED as the default.

The set of safely reclaimable unused initial SIDs across all known
policies is igmp_packet (13), icmp_socket (14), tcp_socket (15), kmod
(24), policy (25), and scmp_packet (26); these initial SIDs were
assigned the same context as unlabeled in all known policies including
mls. If only considering non-mls policies (i.e. assuming that mls
users always upgrade policy with their kernels), the set of safely
reclaimable unused initial SIDs further includes file_labels (6), init
(7), sysctl_modprobe (16), and sysctl_fs (18) through sysctl_dev (23).

Adding new initial SIDs beyond SECINITSID_NUM to policy unfortunately
became a fatal error in commit 24ed7fdae669 ("selinux: use separate
table for initial SID lookup") and even before that it could cause
problems on a policy reload (collision between the new initial SID and
one allocated at runtime) ever since commit 42596eafdd75 ("selinux:
load the initial SIDs upon every policy load") so we cannot safely
start adding new initial SIDs to policies beyond SECINITSID_NUM (27)
until such a time as all such kernels do not need to be supported and
only those that include this commit are relevant. That is not a big
deal since we haven't added a new initial SID since 2004 (v2.6.7) and
we have plenty of unused ones we can reclaim if we truly need one.

If we want to avoid the wasted storage in initial_sid_to_string[]
and/or sidtab->isids[] for the unused initial SIDs, we could introduce
an indirection between the kernel initial SID values and the policy
initial SID values and just map the policy SID values in the ocontexts
to the kernel values during policy_load_isids(). Originally I thought
we'd do this by preserving the initial SID names in the kernel policy
and creating a mapping at load time like we do for the security
classes and permissions but that would require a new kernel policy
format version and associated changes to libsepol/checkpolicy and I'm
not sure it is justified. Simpler approach is just to create a fixed
mapping table in the kernel from the existing fixed policy values to
the kernel values. Less flexible but probably sufficient.

A separate selinux userspace change was applied in
https://github.com/SELinuxProject/selinux/commit/8677ce5e8f592950ae6f14cea1b68a20ddc1ac25
to enable removal of most of the unused initial SID contexts from
policies, but there is no dependency between that change and this one.
That change permits removing all of the unused initial SID contexts
from policy except for the fs and sysctl SID contexts. The initial
SID declarations themselves would remain in policy to preserve the
values of subsequent ones but the contexts can be dropped. If/when
the kernel decides to reuse one of them, future policies can change
the name and start assigning a context again without breaking
compatibility.

Here is how I would envision staging changes to the initial SIDs in a
compatible manner after this commit is applied:

1. At any time after this commit is applied, the kernel could choose
to reclaim one of the safely reclaimable unused initial SIDs listed
above for a new purpose (i.e. replace its NULL entry in the
initial_sid_to_string[] table with a new name and start using the
newly generated SECINITSID_name symbol in code), and refpolicy could
at that time rename its declaration of that initial SID to reflect its
new purpose and start assigning it a context going
forward. Existing/old policies would map the reclaimed initial SID to
the unlabeled context, so that would be the initial default behavior
until policies are updated. This doesn't depend on the selinux
userspace change; it will work with existing policies and userspace.

2. In 6 months or so we'll have another SELinux userspace release that
will include the libsepol/checkpolicy support for omitting unused
initial SID contexts.

3. At any time after that release, refpolicy can make that release its
minimum build requirement and drop the sid context statements (but not
the sid declarations) for all of the unused initial SIDs except for
fs and sysctl, which must remain for compatibility on policy
reload with old kernels and for compatibility with kernels that were
still using SECINITSID_SYSCTL (< 2.6.39). This doesn't depend on this
kernel commit; it will work with previous kernels as well.

4. After N years for some value of N, refpolicy decides that it no
longer cares about policy reload compatibility for kernels that
predate this kernel commit, and refpolicy drops the fs and sysctl
SID contexts from policy too (but retains the declarations).

5. After M years for some value of M, the kernel decides that it no
longer cares about compatibility with refpolicies that predate step 4
(dropping the fs and sysctl SIDs), and those two SIDs also become
safely reclaimable. This step is optional and need not ever occur unless
we decide that the need to reclaim those two SIDs outweighs the
compatibility cost.

6. After O years for some value of O, refpolicy decides that it no
longer cares about policy load (not just reload) compatibility for
kernels that predate this kernel commit, and both kernel and refpolicy
can then start adding and using new initial SIDs beyond 27. This does
not depend on the previous change (step 5) and can occur independent
of it.

Fixes: https://github.com/SELinuxProject/selinux-kernel/issues/12
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: optimize storage of filename transitions

In these rules, each rule with the same (target type, target class,
filename) values is (in practice) always mapped to the same result type.
Therefore, it is much more efficient to group the rules by (ttype,
tclass, filename).

Thus, this patch drops the stype field from the key and changes the
datum to be a linked list of one or more structures that contain a
result type and an ebitmap of source types that map the given target to
the given result type under the given filename. The size of the hash
table is also incremented to 2048 to be more optimal for Fedora policy
(which currently has ~2500 unique (ttype, tclass, filename) tuples,
regardless of whether the 'unconfined' module is enabled).

Not only does this dramtically reduce memory usage when the policy
contains a lot of unconfined domains (ergo a lot of filename based
transitions), but it also slightly reduces memory usage of strongly
confined policies (modeled on Fedora policy with 'unconfined' module
disabled) and significantly reduces lookup times of these rules on
Fedora (roughly matches the performance of the rhashtable conversion
patch [1] posted recently to selinux@vger.kernel.org).

An obvious next step is to change binary policy format to match this
layout, so that disk space is also saved. However, since that requires
more work (including matching userspace changes) and this patch is
already beneficial on its own, I'm posting it separately.

Performance/memory usage comparison:

Kernel | Policy load | Policy load | Mem usage | Mem usage | openbench
| | (-unconfined) | | (-unconfined) | (createfiles)
-----------------|-------------|---------------|-----------|---------------|--------------
reference | 1,30s | 0,91s | 90MB | 77MB | 55 us/file
rhashtable patch | 0.98s | 0,85s | 85MB | 75MB | 38 us/file
this patch | 0,95s | 0,87s | 75MB | 75MB | 40 us/file

(Memory usage is measured after boot. With SELinux disabled the memory
usage was ~60MB on the same system.)

[1] https://lore.kernel.org/selinux/20200116213937.77795-1-dev@lynxeye.de/T/

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: generalize evaluate_cond_node()

Both callers iterate the cond_list and call it for each node - turn it
into evaluate_cond_nodes(), which does the iteration for them.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: convert cond_list to array

Since it is fixed-size after allocation and we know the size beforehand,
using a plain old array is simpler and more efficient.

While there, also fix signedness of some related variables/parameters.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: allow kernfs symlinks to inherit parent directory context

Currently symlinks on kernel filesystems, like sysfs, are labeled on
creation with the parent filesystem root sid.

Allow symlinks to inherit the parent directory context, so fine-grained
kernfs labeling can be applied to symlinks too and checking contexts
doesn't complain about them.

For backward-compatibility this behavior is contained in a new policy
capability: genfs_seclabel_symlinks

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: simplify evaluate_cond_node()

It never fails, so it can just return void.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: move status variables out of selinux_ss

It fits more naturally in selinux_state, since it reflects also global
state (the enforcing and policyload fields).

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: do not allocate ancillary buffer on first load

In security_load_policy(), we can defer allocating the newpolicydb
ancillary array to after checking state->initialized, thereby avoiding
the pointless allocation when loading policy the first time.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: merged portions by hand]
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: treat atomic flags more carefully

The disabled/enforcing/initialized flags are all accessed concurrently
by threads so use the appropriate accessors that ensure atomicity and
document that it is expected.

Use smp_load/acquire...() helpers (with memory barriers) for the
initialized flag, since it gates access to the rest of the state
structures.

Note that the disabled flag is currently not used for anything other
than avoiding double disable, but it will be used for bailing out of
hooks once security_delete_hooks() is removed.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: remove set but not used variable 'sidtab'

security/selinux/ss/services.c: In function security_port_sid:
security/selinux/ss/services.c:2346:17: warning: variable sidtab set but not used [-Wunused-but-set-variable]
security/selinux/ss/services.c: In function security_ib_endport_sid:
security/selinux/ss/services.c:2435:17: warning: variable sidtab set but not used [-Wunused-but-set-variable]
security/selinux/ss/services.c: In function security_netif_sid:
security/selinux/ss/services.c:2480:17: warning: variable sidtab set but not used [-Wunused-but-set-variable]
security/selinux/ss/services.c: In function security_fs_use:
security/selinux/ss/services.c:2831:17: warning: variable sidtab set but not used [-Wunused-but-set-variable]

Since commit 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table")
'sidtab' is not used any more, so remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: ensure the policy has been loaded before reading the sidtab stats

Check to make sure we have loaded a policy before we query the
sidtab's hash stats. Failure to do so could result in a kernel
panic/oops due to a dereferenced NULL pointer.

Fixes: 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: cache the SID -> context string translation

Translating a context struct to string can be quite slow, especially if
the context has a lot of category bits set. This can cause quite
noticeable performance impact in situations where the translation needs
to be done repeatedly. A common example is a UNIX datagram socket with
the SO_PASSSEC option enabled, which is used e.g. by systemd-journald
when receiving log messages via datagram socket. This scenario can be
reproduced with:

cat /dev/urandom | base64 | logger &
timeout 30s perf record -p $(pidof systemd-journald) -a -g
kill %1
perf report -g none --pretty raw | grep security_secid_to_secctx

Before the caching introduced by this patch, computing the context
string (security_secid_to_secctx() function) takes up ~65% of
systemd-journald's CPU time (assuming a context with 1024 categories
set and Fedora x86_64 release kernel configs). After this patch
(assuming near-perfect cache hit ratio) this overhead is reduced to just
~2%.

This patch addresses the issue by caching a certain number (compile-time
configurable) of recently used context strings to speed up repeated
translations of the same context, while using only a small amount of
memory.

The cache is integrated into the existing sidtab table by adding a field
to each entry, which when not NULL contains an RCU-protected pointer to
a cache entry containing the cached string. The cache entries are kept
in a linked list sorted according to how recently they were used. On a
cache miss when the cache is full, the least recently used entry is
removed to make space for the new entry.

The patch migrates security_sid_to_context_core() to use the cache (also
a few other functions where it was possible without too much fuss, but
these mostly use the translation for logging in case of error, which is
rare).

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1733259
Cc: Michal Sekletar <msekleta@redhat.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Tested-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
[PM: lots of merge fixups due to collisions with other sidtab patches]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: sidtab reverse lookup hash table

This replaces the reverse table lookup and reverse cache with a
hashtable which improves cache-miss reverse-lookup times from
O(n) to O(1)* and maintains the same performance as a reverse
cache hit.

This reduces the time needed to add a new sidtab entry from ~500us
to 5us on a Pixel 3 when there are ~10,000 sidtab entries.

The implementation uses the kernel's generic hashtable API,
It uses the context's string represtation as the hash source,
and the kernels generic string hashing algorithm full_name_hash()
to reduce the string to a 32 bit value.

This change also maintains the improvement introduced in
commit ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve
performance") which removed the need to keep the current sidtab
locked during policy reload. It does however introduce periodic
locking of the target sidtab while converting the hashtable. Sidtab
entries are never modified or removed, so the context struct stored
in the sid_to_context tree can also be used for the context_to_sid
hashtable to reduce memory usage.

This bug was reported by:
- On the selinux bug tracker.
BUG: kernel softlockup due to too many SIDs/contexts #37
https://github.com/SELinuxProject/selinux-kernel/issues/37
- Jovana Knezevic on Android's bugtracker.
Bug: 140252993
"During multi-user performance testing, we create and remove users
many times. selinux_android_restorecon_pkgdir goes from 1ms to over
20ms after about 200 user creations and removals. Accumulated over
~280 packages, that adds a significant time to user creation,
making perf benchmarks unreliable."

* Hashtable lookup is only O(1) when n < the number of buckets.

Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Reported-by: Stephen Smalley <sds@tycho.nsa.gov>
Reported-by: Jovana Knezevic <jovanak@google.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Tested-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: subj tweak, removed changelog from patch description]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix context string corruption in convert_context()

string_to_context_struct() may garble the context string, so we need to
copy back the contents again from the old context struct to avoid
storing the corrupted context.

Since string_to_context_struct() tokenizes (and therefore truncates) the
context string and we are later potentially copying it with kstrdup(),
this may eventually cause pieces of uninitialized kernel memory to be
disclosed to userspace (when copying to userspace based on the stored
length and not the null character).

How to reproduce on Fedora and similar:
# dnf install -y memcached
# systemctl start memcached
# semodule -d memcached
# load_policy
# load_policy
# systemctl stop memcached
# ausearch -m AVC
type=AVC msg=audit(1570090572.648:313): avc: denied { signal } for pid=1 comm="systemd" scontext=system_u:system_r:init_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=process permissive=0 trawcon=73797374656D5F75007400000000000070BE6E847296FFFF726F6D000096FFFF76

Cc: stable@vger.kernel.org
Reported-by: Milos Malik <mmalik@redhat.com>
Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: policydb - rename type_val_to_struct_array

The name is overly long and inconsistent with the other *_val_to_struct
members. Dropping the "_array" prefix makes the code easier to read and
gets rid of one line over 80 characters warning.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: format all invalid context as untrusted

The userspace tools expect all fields of the same name to be logged
consistently with the same encoding. Since the invalid_context fields
contain untrusted strings in selinux_inode_setxattr()
and selinux_setprocattr(), encode all instances of this field the same
way as though they were untrusted even though
compute_sid_handle_invalid_context() and security_sid_mls_copy() are
trusted.

Please see github issue
https://github.com/linux-audit/audit-kernel/issues/57

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selinux: remove some no-op BUG_ONs

Since acdf52d97f82 ("selinux: convert to kvmalloc"), these check whether
an address-of value is NULL, which is pointless.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: remove useless assignments

The code incorrectly assigned directly to the variables instead of the
values they point to. Since the values are already set to NULL/0 at the
beginning of the function, we can simply remove these useless
assignments.

Reported-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Fixes: fede148324c3 ("selinux: log invalid contexts in AVCs")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: removed a bad comment that was causing compiler warnings]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: convert to kvmalloc

The flex arrays were being used for constant sized arrays, so there's no
benefit to using flex_arrays over something simpler.

Link: http://lkml.kernel.org/r/20181217131929.11727-4-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

audit: remove unused actx param from audit_rule_match

The audit_rule_match() struct audit_context *actx parameter is not used
by any in-tree consumers (selinux, apparmour, integrity, smack).

The audit context is an internal audit structure that should only be
accessed by audit accessor functions.

It was part of commit 03d37d25e0f9 ("LSM/Audit: Introduce generic
Audit LSM hooks") but appears to have never been used.

Remove it.

Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/107

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the referenced commit title]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: log invalid contexts in AVCs

In case a file has an invalid context set, in an AVC record generated
upon access to such file, the target context is always reported as
unlabeled. This patch adds new optional fields to the AVC record
(srawcon and trawcon) that report the actual context string if it
differs from the one reported in scontext/tcontext. This is useful for
diagnosing SELinux denials involving invalid contexts.

To trigger an AVC that illustrates this situation:

# setenforce 0
# touch /tmp/testfile
# setfattr -n security.selinux -v system_u:object_r:banana_t:s0 /tmp/testfile
# runcon system_u:system_r:sshd_t:s0 cat /tmp/testfile

AVC before:

type=AVC msg=audit(1547801083.248:11): avc: denied { open } for pid=1149 comm="cat" path="/tmp/testfile" dev="tmpfs" ino=6608 scontext=system_u:system_r:sshd_t:s0 tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=file permissive=1

AVC after:

type=AVC msg=audit(1547801083.248:11): avc: denied { open } for pid=1149 comm="cat" path="/tmp/testfile" dev="tmpfs" ino=6608 scontext=system_u:system_r:sshd_t:s0 tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=file permissive=1 trawcon=system_u:object_r:banana_t:s0

Note that it is also possible to encounter this situation with the
'scontext' field - e.g. when a new policy is loaded while a process is
running, whose context is not valid in the new policy.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1135683

Cc: Daniel Walsh <dwalsh@redhat.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

SELinux: Remove unused selinux_is_enabled

There are no longer users of selinux_is_enabled().
Remove it. As selinux_is_enabled() is the only reason
for include/linux/selinux.h remove that as well.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

selinux: overhaul sidtab to fix bug and improve performance

Before this patch, during a policy reload the sidtab would become frozen
and trying to map a new context to SID would be unable to add a new
entry to sidtab and fail with -ENOMEM.

Such failures are usually propagated into userspace, which has no way of
distignuishing them from actual allocation failures and thus doesn't
handle them gracefully. Such situation can be triggered e.g. by the
following reproducer:

while true; do load_policy; echo -n .; sleep 0.1; done &
for (( i = 0; i < 1024; i++ )); do
runcon -l s0:c$i echo -n x || break
# or:
# chcon -l s0:c$i <some_file> || break
done

This patch overhauls the sidtab so it doesn't need to be frozen during
policy reload, thus solving the above problem.

The new SID table leverages the fact that SIDs are allocated
sequentially and are never invalidated and stores them in linear buckets
indexed by a tree structure. This brings several advantages:
1. Fast SID -> context lookup - this lookup can now be done in
logarithmic time complexity (usually in less than 4 array lookups)
and can still be done safely without locking.
2. No need to re-search the whole table on reverse lookup miss - after
acquiring the spinlock only the newly added entries need to be
searched, which means that reverse lookups that end up inserting a
new entry are now about twice as fast.
3. No need to freeze sidtab during policy reload - it is now possible
to handle insertion of new entries even during sidtab conversion.

The tree structure of the new sidtab is able to grow automatically to up
to about 2^31 entries (at which point it should not have more than about
4 tree levels). The old sidtab had a theoretical capacity of almost 2^32
entries, but half of that is still more than enough since by that point
the reverse table lookups would become unusably slow anyway...

The number of entries per tree node is selected automatically so that
each node fits into a single page, which should be the easiest size for
kmalloc() to handle.

Note that the cache for reverse lookup is preserved with equivalent
logic. The only difference is that instead of storing pointers to the
hash table nodes it stores just the indices of the cached entries.

The new cache ensures that the indices are loaded/stored atomically, but
it still has the drawback that concurrent cache updates may mess up the
contents of the cache. Such situation however only reduces its
effectivity, not the correctness of lookups.

Tested by selinux-testsuite and thoroughly tortured by this simple
stress test:
```
function rand_cat() {
echo $(( $RANDOM % 1024 ))
}

function do_work() {
while true; do
echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \
>/sys/fs/selinux/context 2>/dev/null || true
done
}

do_work >/dev/null &
do_work >/dev/null &
do_work >/dev/null &

while load_policy; do echo -n .; sleep 0.1; done

kill %1
kill %2
kill %3
```

Link: https://github.com/SELinuxProject/selinux-kernel/issues/38

Reported-by: Orion Poplawski <orion@nwra.com>
Reported-by: Li Kun <hw.likun@huawei.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: most of sidtab.c merged by hand due to conflicts]
[PM: checkpatch fixes in mls.c, services.c, sidtab.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: use separate table for initial SID lookup

This moves handling of initial SIDs into a separate table. Note that the
SIDs stored in the main table are now shifted by SECINITSID_NUM and
converted to/from the actual SIDs transparently by helper functions.

This change doesn't make much sense on its own, but it simplifies
further sidtab overhaul in a succeeding patch.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: fixed some checkpatch warnings on line length, whitespace]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: make "selinux_policycap_names[]" const char *

Those strings aren't written.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: refactor sidtab conversion

This is a purely cosmetic change that encapsulates the three-step sidtab
conversion logic (shutdown -> clone -> map) into a single function
defined in sidtab.c (as opposed to services.c).

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: whitespaces fixes to make checkpatch happy]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: refactor mls_context_to_sid() and make it stricter

The intended behavior change for this patch is to reject any MLS strings
that contain (trailing) garbage if p->mls_enabled is true.

As suggested by Paul Moore, change mls_context_to_sid() so that the two
parts of the range are extracted before the rest of the parsing. Because
now we don't have to scan for two different separators simultaneously
everywhere, we can actually switch to strchr() everywhere instead of the
open-coded loops that scan for two separators at once.

mls_context_to_sid() used to signal how much of the input string was parsed
by updating `*scontext`. However, there is actually no case in which
mls_context_to_sid() only parses a subset of the input and still returns
a success (other than the buggy case with a second '-' in which it
incorrectly claims to have consumed the entire string). Turn `scontext`
into a simple pointer argument and stop redundantly checking whether the
entire input was consumed in string_to_context_struct(). This also lets us
remove the `scontext_len` argument from `string_to_context_struct()`.

Signed-off-by: Jann Horn <jannh@google.com>
[PM: minor merge fuzz in convert_context()]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Cleanup printk logging in services

Replace printk with pr_* to avoid checkpatch warnings.

Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

selinux: KASAN: slab-out-of-bounds in xattr_getsecurity

Call trace:
[<ffffff9203a8d7a8>] dump_backtrace+0x0/0x428
[<ffffff9203a8dbf8>] show_stack+0x28/0x38
[<ffffff920409bfb8>] dump_stack+0xd4/0x124
[<ffffff9203d187e8>] print_address_description+0x68/0x258
[<ffffff9203d18c00>] kasan_report.part.2+0x228/0x2f0
[<ffffff9203d1927c>] kasan_report+0x5c/0x70
[<ffffff9203d1776c>] check_memory_region+0x12c/0x1c0
[<ffffff9203d17cdc>] memcpy+0x34/0x68
[<ffffff9203d75348>] xattr_getsecurity+0xe0/0x160
[<ffffff9203d75490>] vfs_getxattr+0xc8/0x120
[<ffffff9203d75d68>] getxattr+0x100/0x2c8
[<ffffff9203d76fb4>] SyS_fgetxattr+0x64/0xa0
[<ffffff9203a83f70>] el0_svc_naked+0x24/0x28

If user get root access and calls security.selinux setxattr() with an
embedded NUL on a file and then if some process performs a getxattr()
on that file with a length greater than the actual length of the string,
it would result in a panic.

To fix this, add the actual length of the string to the security context
instead of the length passed by the userspace process.

Signed-off-by: Sachin Grover <sgrover@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use inline function to get audit context

Recognizing that the audit context is an internal audit value, use an
access function to retrieve the audit context pointer for the task
rather than reaching directly into the task struct to get it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: wrap AVC state

Wrap the AVC state within the selinux_state structure and
pass it explicitly to all AVC functions. The AVC private state
is encapsulated in a selinux_avc structure that is referenced
from the selinux_state.

This change should have no effect on SELinux behavior or
APIs (userspace or LSM).

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: fix handling of uninitialized selinux state in get_bools/classes

If security_get_bools/classes are called before the selinux state is
initialized (i.e. before first policy load), then they should just
return immediately with no booleans/classes.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: rename the {is,set}_enforcing() functions

Rename is_enforcing() to enforcing_enabled() and
enforcing_set() to set_enforcing().

Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: wrap global selinux state

Define a selinux state structure (struct selinux_state) for
global SELinux state and pass it explicitly to all security server
functions. The public portion of the structure contains state
that is used throughout the SELinux code, such as the enforcing mode.
The structure also contains a pointer to a selinux_ss structure whose
definition is private to the security server and contains security
server specific state such as the policy database and SID table.

This change should have no effect on SELinux behavior or APIs
(userspace or LSM). It merely wraps SELinux state and passes it
explicitly as needed.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: minor fixups needed due to collisions with the SCTP patches]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: skip bounded transition processing if the policy isn't loaded

We can't do anything reasonable in security_bounded_transition() if we
don't have a policy loaded, and in fact we could run into problems
with some of the code inside expecting a policy. Fix these problems
like we do many others in security/selinux/ss/services.c by checking
to see if the policy is loaded (ss_initialized) and returning quickly
if it isn't.

Reported-by: syzbot <syzkaller-bugs@googlegroups.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: James Morris <james.l.morris@oracle.com>

selinux: ensure the context is NUL terminated in security_context_to_sid_core()

The syzbot/syzkaller automated tests found a problem in
security_context_to_sid_core() during early boot (before we load the
SELinux policy) where we could potentially feed context strings without
NUL terminators into the strcmp() function.

We already guard against this during normal operation (after the SELinux
policy has been loaded) by making a copy of the context strings and
explicitly adding a NUL terminator to the end. The patch extends this
protection to the early boot case (no loaded policy) by moving the context
copy earlier in security_context_to_sid_core().

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Reviewed-By: William Roberts <william.c.roberts@intel.com>

selinux: Use kmem_cache for hashtab_node

During random test as own device to check slub account,
we found some slack memory from hashtab_node(kmalloc-64).
By using kzalloc(), middle of test result like below:
allocated size 240768
request size 45144
slack size 195624
allocation count 3762

So, we want to use kmem_cache_zalloc() and that
can reduce memory size 52byte(slack size/alloc count) per each struct.

Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: update my email address

Update my email address since epoch.ncsc.mil no longer exists.
MAINTAINERS and CREDITS are already correct.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Generalize support for NNP/nosuid SELinux domain transitions

As systemd ramps up enabling NNP (NoNewPrivileges) for system services,
it is increasingly breaking SELinux domain transitions for those services
and their descendants. systemd enables NNP not only for services whose
unit files explicitly specify NoNewPrivileges=yes but also for services
whose unit files specify any of the following options in combination with
running without CAP_SYS_ADMIN (e.g. specifying User= or a
CapabilityBoundingSet= without CAP_SYS_ADMIN): SystemCallFilter=,
SystemCallArchitectures=, RestrictAddressFamilies=, RestrictNamespaces=,
PrivateDevices=, ProtectKernelTunables=, ProtectKernelModules=,
MemoryDenyWriteExecute=, or RestrictRealtime= as per the systemd.exec(5)
man page.

The end result is bad for the security of both SELinux-disabled and
SELinux-enabled systems. Packagers have to turn off these
options in the unit files to preserve SELinux domain transitions. For
users who choose to disable SELinux, this means that they miss out on
at least having the systemd-supported protections. For users who keep
SELinux enabled, they may still be missing out on some protections
because it isn't necessarily guaranteed that the SELinux policy for
that service provides the same protections in all cases.

commit 7b0d0b40cd78 ("selinux: Permit bounded transitions under
NO_NEW_PRIVS or NOSUID.") allowed bounded transitions under NNP in
order to support limited usage for sandboxing programs. However,
defining typebounds for all of the affected service domains
is impractical to implement in policy, since typebounds requires us
to ensure that each domain is allowed everything all of its descendant
domains are allowed, and this has to be repeated for the entire chain
of domain transitions. There is no way to clone all allow rules from
descendants to their ancestors in policy currently, and doing so would
be undesirable even if it were practical, as it requires leaking
permissions to objects and operations into ancestor domains that could
weaken their own security in order to allow them to the descendants
(e.g. if a descendant requires execmem permission, then so do all of
its ancestors; if a descendant requires execute permission to a file,
then so do all of its ancestors; if a descendant requires read to a
symbolic link or temporary file, then so do all of its ancestors...).
SELinux domains are intentionally not hierarchical / bounded in this
manner normally, and making them so would undermine their protections
and least privilege.

We have long had a similar tension with SELinux transitions and nosuid
mounts, albeit not as severe. Users often have had to choose between
retaining nosuid on a mount and allowing SELinux domain transitions on
files within those mounts. This likewise leads to unfortunate tradeoffs
in security.

Decouple NNP/nosuid from SELinux transitions, so that we don't have to
make a choice between them. Introduce a nnp_nosuid_transition policy
capability that enables transitions under NNP/nosuid to be based on
a permission (nnp_transition for NNP; nosuid_transition for nosuid)
between the old and new contexts in addition to the current support
for bounded transitions. Domain transitions can then be allowed in
policy without requiring the parent to be a strict superset of all of
its children.

With this change, systemd unit files can be left unmodified from upstream.
SELinux-disabled and SELinux-enabled users will benefit from retaining any
of the systemd-provided protections. SELinux policy will only need to
be adapted to enable the new policy capability and to allow the
new permissions between domain pairs as appropriate.

NB: Allowing nnp_transition between two contexts opens up the potential
for the old context to subvert the new context by installing seccomp
filters before the execve. Allowing nosuid_transition between two contexts
opens up the potential for a context transition to occur on a file from
an untrusted filesystem (e.g. removable media or remote filesystem). Use
with care.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: use kmem_cache for ebitmap

The allocated size for each ebitmap_node is 192byte by kzalloc().
Then, ebitmap_node size is fixed, so it's possible to use only 144byte
for each object by kmem_cache_zalloc().
It can reduce some dynamic allocation size.

Signed-off-by: Junil Lee <junil0814.lee@lge.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Add IB Port SMP access vector

Add a type for Infiniband ports and an access vector for subnet
management packets. Implement the ib_port_smp hook to check that the
caller has permission to send and receive SMPs on the end port specified
by the device name and port. Add interface to query the SID for a IB
port, which walks the IB_PORT ocontexts to find an entry for the
given name and port.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Implement Infiniband PKey "Access" access vector

Add a type and access vector for PKeys. Implement the ib_pkey_access
hook to check that the caller has permission to access the PKey on the
given subnet prefix. Add an interface to get the PKey SID. Walk the PKey
ocontexts to find an entry for the given subnet prefix and pkey.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: log policy capability state when a policy is loaded

Log the state of SELinux policy capabilities when a policy is loaded.
For each policy capability known to the kernel, log the policy capability
name and the value set in the policy. For policy capabilities that are
set in the loaded policy but unknown to the kernel, log the policy
capability index, since this is the only information presently available
in the policy.

Sample output with a policy created with a new capability defined
that is not known to the kernel:
SELinux: policy capability network_peer_controls=1
SELinux: policy capability open_perms=1
SELinux: policy capability extended_socket_class=1
SELinux: policy capability always_check_network=0
SELinux: policy capability cgroup_seclabel=0
SELinux: unknown policy capability 5

Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/32

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Remove unnecessary check of array base in selinux_set_mapping()

'perms' will never be NULL since it isn't a plain pointer but an array
of u32 values.

This fixes the following warning when building with clang:

security/selinux/ss/services.c:158:16: error: address of array
'p_in->perms' will always evaluate to 'true'
[-Werror,-Wpointer-bool-conversion]
while (p_in->perms && p_in->perms[k]) {

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: wrap cgroup seclabel support with its own policy capability

commit 1ea0ce40690dff38935538e8dab7b12683ded0d3 ("selinux: allow
changing labels for cgroupfs") broke the Android init program,
which looks up security contexts whenever creating directories
and attempts to assign them via setfscreatecon().
When creating subdirectories in cgroup mounts, this would previously
be ignored since cgroup did not support userspace setting of security
contexts. However, after the commit, SELinux would attempt to honor
the requested context on cgroup directories and fail due to permission
denial. Avoid breaking existing userspace/policy by wrapping this change
with a conditional on a new cgroup_seclabel policy capability. This
preserves existing behavior until/unless a new policy explicitly enables
this capability.

Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

selinux: support distinctions among all network address families

Extend SELinux to support distinctions among all network address families
implemented by the kernel by defining new socket security classes
and mapping to them. Otherwise, many sockets are mapped to the generic
socket class and are indistinguishable in policy. This has come up
previously with regard to selectively allowing access to bluetooth sockets,
and more recently with regard to selectively allowing access to AF_ALG
sockets. Guido Trentalancia submitted a patch that took a similar approach
to add only support for distinguishing AF_ALG sockets, but this generalizes
his approach to handle all address families implemented by the kernel.
Socket security classes are also added for ICMP and SCTP sockets.
Socket security classes were not defined for AF_* values that are reserved
but unimplemented in the kernel, e.g. AF_NETBEUI, AF_SECURITY, AF_ASH,
AF_ECONET, AF_SNA, AF_WANPIPE.

Backward compatibility is provided by only enabling the finer-grained
socket classes if a new policy capability is set in the policy; older
policies will behave as before. The legacy redhat1 policy capability
that was only ever used in testing within Fedora for ptrace_child
is reclaimed for this purpose; as far as I can tell, this policy
capability is not enabled in any supported distro policy.

Add a pair of conditional compilation guards to detect when new AF_* values
are added so that we can update SELinux accordingly rather than having to
belatedly update it long after new address families are introduced.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Only apply bounds checking to source types

The current bounds checking of both source and target types
requires allowing any domain that has access to the child
domain to also have the same permissions to the parent, which
is undesirable. Drop the target bounds checking.

KaiGai Kohei originally removed all use of target bounds in
commit 7d52a155e38d ("selinux: remove dead code in
type_attribute_bounds_av()") but this was reverted in
commit 2ae3ba39389b ("selinux: libsepol: remove dead code in
check_avtab_hierarchy_callback()") because it would have
required explicitly allowing the parent any permissions
to the child that the child is allowed to itself.

This change in contrast retains the logic for the case where both
source and target types are bounded, thereby allowing access
if the parent of the source is allowed the corresponding
permissions to the parent of the target. Further, this change
reworks the logic such that we only perform a single computation
for each case and there is no ambiguity as to how to resolve
a bounds violation.

Under the new logic, if the source type and target types are both
bounded, then the parent of the source type must be allowed the same
permissions to the parent of the target type. If only the source
type is bounded, then the parent of the source type must be allowed
the same permissions to the target type.

Examples of the new logic and comparisons with the old logic:
1. If we have:
typebounds A B;
then:
allow B self:process <permissions>;
will satisfy the bounds constraint iff:
allow A self:process <permissions>;
is also allowed in policy.

Under the old logic, the allow rule on B satisfies the
bounds constraint if any of the following three are allowed:
allow A B:process <permissions>; or
allow B A:process <permissions>; or
allow A self:process <permissions>;
However, either of the first two ultimately require the third to
satisfy the bounds constraint under the old logic, and therefore
this degenerates to the same result (but is more efficient - we only
need to perform one compute_av call).

2. If we have:
typebounds A B;
typebounds A_exec B_exec;
then:
allow B B_exec:file <permissions>;
will satisfy the bounds constraint iff:
allow A A_exec:file <permissions>;
is also allowed in policy.

This is essentially the same as #1; it is merely included as
an example of dealing with object types related to a bounded domain
in a manner that satisfies the bounds relationship. Note that
this approach is preferable to leaving B_exec unbounded and having:
allow A B_exec:file <permissions>;
in policy because that would allow B's entrypoints to be used to
enter A. Similarly for _tmp or other related types.

3. If we have:
typebounds A B;
and an unbounded type T, then:
allow B T:file <permissions>;
will satisfy the bounds constraint iff:
allow A T:file <permissions>;
is allowed in policy.

The old logic would have been identical for this example.

4. If we have:
typebounds A B;
and an unbounded domain D, then:
allow D B:unix_stream_socket <permissions>;
is not subject to any bounds constraints under the new logic
because D is not bounded. This is desirable so that we can
allow a domain to e.g. connectto a child domain without having
to allow it to do the same to its parent.

The old logic would have required:
allow D A:unix_stream_socket <permissions>;
to also be allowed in policy.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: re-wrapped description to appease checkpatch.pl]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: Change bool variable name to index.

security_get_bool_value(int bool) argument "bool" conflicts with
in-kernel macros such as BUILD_BUG(). This patch changes this to
index which isn't a type.

Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andrew Perepechko <anserper@ya.ru>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: selinux@tycho.nsa.gov
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Moore <pmoore@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
[PM: wrapped description for checkpatch.pl, use "selinux:..." as subj]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux: export validatetrans decisions

Make validatetrans decisions available through selinuxfs.
"/validatetrans" is added to selinuxfs for this purpose.
This functionality is needed by file system servers
implemented in userspace or kernelspace without the VFS
layer.

Writing "$oldcontext $newcontext $tclass $taskcontext"
to /validatetrans is expected to return 0 if the transition
is allowed and -EPERM otherwise.

Signed-off-by: Andrew Perepechko <anserper@ya.ru>
CC: andrew.perepechko@seagate.com
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: use sprintf return value

sprintf returns the number of characters printed (excluding '\0'), so
we can use that and avoid duplicating the length computation.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: use kstrdup() in security_get_bools()

This is much simpler.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: use kmemdup in security_sid_to_context_core()

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: introduce security_context_str_to_sid

There seems to be a little confusion as to whether the scontext_len
parameter of security_context_to_sid() includes the nul-byte or
not. Reading security_context_to_sid_core(), it seems that the
expectation is that it does not (both the string copying and the test
for scontext_len being zero hint at that).

Introduce the helper security_context_str_to_sid() to do the strlen()
call and fix all callers.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: extended permissions for ioctls

Add extended permissions logic to selinux. Extended permissions
provides additional permissions in 256 bit increments. Extend the
generic ioctl permission check to use the extended permissions for
per-command filtering. Source/target/class sets including the ioctl
permission may additionally include a set of commands. Example:

allowxperm <source> <target>:<class> ioctl unpriv_app_socket_cmds
auditallowxperm <source> <target>:<class> ioctl priv_gpu_cmds

Where unpriv_app_socket_cmds and priv_gpu_cmds are macros
representing commonly granted sets of ioctl commands.

When ioctl commands are omitted only the permissions are checked.
This feature is intended to provide finer granularity for the ioctl
permission that may be too imprecise. For example, the same driver
may use ioctls to provide important and benign functionality such as
driver version or socket type as well as dangerous capabilities such
as debugging features, read/write/execute to physical memory or
access to sensitive data. Per-command filtering provides a mechanism
to reduce the attack surface of the kernel, and limit applications
to the subset of commands required.

The format of the policy binary has been modified to include ioctl
commands, and the policy version number has been incremented to
POLICYDB_VERSION_XPERMS_IOCTL=30 to account for the format
change.

The extended permissions logic is deliberately generic to allow
components to be reused e.g. netlink filters

Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Acked-by: Nick Kralevich <nnk@google.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: reconcile security_netlbl_secattr_to_sid() and mls_import_netlbl_cat()

Move the NetLabel secattr MLS category import logic into
mls_import_netlbl_cat() where it belongs, and use the
mls_import_netlbl_cat() function in security_netlbl_secattr_to_sid().

Reported-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: normalize audit log formatting

Restructure to keyword=value pairs without spaces. Drop superfluous words in
text. Make invalid_context a keyword. Change result= keyword to seresult=.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[Minor rewrite to the patch subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: no recursive read_lock of policy_rwlock in security_genfs_sid()

With the introduction of fair queued rwlock, recursive read_lock()
may hang the offending process if there is a write_lock() somewhere
in between.

With recursive read_lock checking enabled, the following error was
reported:

=============================================
[ INFO: possible recursive locking detected ]
3.16.0-rc1 #2 Tainted: G E
---------------------------------------------
load_policy/708 is trying to acquire lock:
(policy_rwlock){.+.+..}, at: [<ffffffff8125b32a>]
security_genfs_sid+0x3a/0x170

but task is already holding lock:
(policy_rwlock){.+.+..}, at: [<ffffffff8125b48c>]
security_fs_use+0x2c/0x110

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(policy_rwlock);
lock(policy_rwlock);

This patch fixes the occurrence of recursive read_lock() of
policy_rwlock by adding a helper function __security_genfs_sid()
which requires caller to take the lock before calling it. The
security_fs_use() was then modified to call the new helper function.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: add gfp argument to security_xfrm_policy_alloc and fix callers

security_xfrm_policy_alloc can be called in atomic context so the
allocation should be done with GFP_ATOMIC. Add an argument to let the
callers choose the appropriate way. In order to do so a gfp argument
needs to be added to the method xfrm_policy_alloc_security in struct
security_operations and to the internal function
selinux_xfrm_alloc_user. After that switch to GFP_ATOMIC in the atomic
callers and leave GFP_KERNEL as before for the rest.
The path that needed the gfp argument addition is:
security_xfrm_policy_alloc -> security_ops.xfrm_policy_alloc_security ->
all users of xfrm_policy_alloc_security (e.g. selinux_xfrm_policy_alloc) ->
selinux_xfrm_alloc_user (here the allocation used to be GFP_KERNEL only)

Now adding a gfp argument to selinux_xfrm_alloc_user requires us to also
add it to security_context_to_sid which is used inside and prior to this
patch did only GFP_KERNEL allocation. So add gfp argument to
security_context_to_sid and adjust all of its callers as well.

CC: Paul Moore <paul@paul-moore.com>
CC: Dave Jones <davej@redhat.com>
CC: Steffen Klassert <steffen.klassert@secunet.com>
CC: Fan Du <fan.du@windriver.com>
CC: David S. Miller <davem@davemloft.net>
CC: LSM list <linux-security-module@vger.kernel.org>
CC: SELinux list <selinux@tycho.nsa.gov>

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

SELinux: Fix kernel BUG on empty security contexts.

Setting an empty security context (length=0) on a file will
lead to incorrectly dereferencing the type and other fields
of the security context structure, yielding a kernel BUG.
As a zero-length security context is never valid, just reject
all such security contexts whether coming from userspace
via setxattr or coming from the filesystem upon a getxattr
request by SELinux.

Setting a security context value (empty or otherwise) unknown to
SELinux in the first place is only possible for a root process
(CAP_MAC_ADMIN), and, if running SELinux in enforcing mode, only
if the corresponding SELinux mac_admin permission is also granted
to the domain by policy. In Fedora policies, this is only allowed for
specific domains such as livecd for setting down security contexts
that are not defined in the build host policy.

Reproducer:
su
setenforce 0
touch foo
setfattr -n security.selinux foo

Caveat:
Relabeling or removing foo after doing the above may not be possible
without booting with SELinux disabled. Any subsequent access to foo
after doing the above will also trigger the BUG.

BUG output from Matthew Thode:
[ 473.893141] ------------[ cut here ]------------
[ 473.962110] kernel BUG at security/selinux/ss/services.c:654!
[ 473.995314] invalid opcode: 0000 [#6] SMP
[ 474.027196] Modules linked in:
[ 474.058118] CPU: 0 PID: 8138 Comm: ls Tainted: G D I
3.13.0-grsec #1
[ 474.116637] Hardware name: Supermicro X8ST3/X8ST3, BIOS 2.0
07/29/10
[ 474.149768] task: ffff8805f50cd010 ti: ffff8805f50cd488 task.ti:
ffff8805f50cd488
[ 474.183707] RIP: 0010:[<ffffffff814681c7>] [<ffffffff814681c7>]
context_struct_compute_av+0xce/0x308
[ 474.219954] RSP: 0018:ffff8805c0ac3c38 EFLAGS: 00010246
[ 474.252253] RAX: 0000000000000000 RBX: ffff8805c0ac3d94 RCX:
0000000000000100
[ 474.287018] RDX: ffff8805e8aac000 RSI: 00000000ffffffff RDI:
ffff8805e8aaa000
[ 474.321199] RBP: ffff8805c0ac3cb8 R08: 0000000000000010 R09:
0000000000000006
[ 474.357446] R10: 0000000000000000 R11: ffff8805c567a000 R12:
0000000000000006
[ 474.419191] R13: ffff8805c2b74e88 R14: 00000000000001da R15:
0000000000000000
[ 474.453816] FS: 00007f2e75220800(0000) GS:ffff88061fc00000(0000)
knlGS:0000000000000000
[ 474.489254] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 474.522215] CR2: 00007f2e74716090 CR3: 00000005c085e000 CR4:
00000000000207f0
[ 474.556058] Stack:
[ 474.584325] ffff8805c0ac3c98 ffffffff811b549b ffff8805c0ac3c98
ffff8805f1190a40
[ 474.618913] ffff8805a6202f08 ffff8805c2b74e88 00068800d0464990
ffff8805e8aac860
[ 474.653955] ffff8805c0ac3cb8 000700068113833a ffff880606c75060
ffff8805c0ac3d94
[ 474.690461] Call Trace:
[ 474.723779] [<ffffffff811b549b>] ? lookup_fast+0x1cd/0x22a
[ 474.778049] [<ffffffff81468824>] security_compute_av+0xf4/0x20b
[ 474.811398] [<ffffffff8196f419>] avc_compute_av+0x2a/0x179
[ 474.843813] [<ffffffff8145727b>] avc_has_perm+0x45/0xf4
[ 474.875694] [<ffffffff81457d0e>] inode_has_perm+0x2a/0x31
[ 474.907370] [<ffffffff81457e76>] selinux_inode_getattr+0x3c/0x3e
[ 474.938726] [<ffffffff81455cf6>] security_inode_getattr+0x1b/0x22
[ 474.970036] [<ffffffff811b057d>] vfs_getattr+0x19/0x2d
[ 475.000618] [<ffffffff811b05e5>] vfs_fstatat+0x54/0x91
[ 475.030402] [<ffffffff811b063b>] vfs_lstat+0x19/0x1b
[ 475.061097] [<ffffffff811b077e>] SyS_newlstat+0x15/0x30
[ 475.094595] [<ffffffff8113c5c1>] ? __audit_syscall_entry+0xa1/0xc3
[ 475.148405] [<ffffffff8197791e>] system_call_fastpath+0x16/0x1b
[ 475.179201] Code: 00 48 85 c0 48 89 45 b8 75 02 0f 0b 48 8b 45 a0 48
8b 3d 45 d0 b6 00 8b 40 08 89 c6 ff ce e8 d1 b0 06 00 48 85 c0 49 89 c7
75 02 <0f> 0b 48 8b 45 b8 4c 8b 28 eb 1e 49 8d 7d 08 be 80 01 00 00 e8
[ 475.255884] RIP [<ffffffff814681c7>]
context_struct_compute_av+0xce/0x308
[ 475.296120] RSP <ffff8805c0ac3c38>
[ 475.328734] ---[ end trace f076482e9d754adc ]---

Reported-by: Matthew Thode <mthode@mthode.org>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: call WARN_ONCE() instead of calling audit_log_start()

Two of the conditions in selinux_audit_rule_match() should never happen and
the third indicates a race that should be retried. Remove the calls to
audit_log() (which call audit_log_start()) and deal with the errors in the
caller, logging only once if the condition is met. Calling audit_log_start()
in this location makes buffer allocation and locking more complicated in the
calling tree (audit_filter_user()).

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

Revert "selinux: consider filesystem subtype in policies"

This reverts commit 102aefdda4d8275ce7d7100bc16c88c74272b260.

Tom London reports that it causes sync() to hang on Fedora rawhide:

https://bugzilla.redhat.com/show_bug.cgi?id=1033965

and Josh Boyer bisected it down to this commit. Reverting the commit in
the rawhide kernel fixes the problem.

Eric Paris root-caused it to incorrect subtype matching in that commit
breaking fuse, and has a tentative patch, but by now we're better off
retrying this in 3.14 rather than playing with it any more.

Reported-by: Tom London <selinux@gmail.com>
Bisected-by: Josh Boyer <jwboyer@fedoraproject.org>
Acked-by: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Anand Avati <avati@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

selinux: revert 102aefdda4d8275ce7d7100bc16c88c74272b260

Revert "selinux: consider filesystem subtype in policies"

This reverts commit 102aefdda4d8275ce7d7100bc16c88c74272b260.

Explanation from Eric Paris:

SELinux policy can specify if it should use a filesystem's
xattrs or not. In current policy we have a specification that
fuse should not use xattrs but fuse.glusterfs should use
xattrs. This patch has a bug in which non-glusterfs
filesystems would match the rule saying fuse.glusterfs should
use xattrs. If both fuse and the particular filesystem in
question are not written to handle xattr calls during the mount
command, they will deadlock.

I have fixed the bug to do proper matching, however I believe a
revert is still the correct solution. The reason I believe
that is because the code still does not work. The s_subtype is
not set until after the SELinux hook which attempts to match on
the ".gluster" portion of the rule. So we cannot match on the
rule in question. The code is useless.

Signed-off-by: Paul Moore <pmoore@redhat.com>

SELinux: security_load_policy: Silence frame-larger-than warning

Dynamically allocate a couple of the larger stack variables in order to
reduce the stack footprint below 1024. gcc-4.8

security/selinux/ss/services.c: In function 'security_load_policy':
security/selinux/ss/services.c:1964:1: warning: the frame size of 1104 bytes is larger than 1024 bytes [-Wframe-larger-than=]
}

Also silence a couple of checkpatch warnings at the same time.

WARNING: sizeof policydb should be sizeof(policydb)
+ memcpy(oldpolicydb, &policydb, sizeof policydb);

WARNING: sizeof policydb should be sizeof(policydb)
+ memcpy(&policydb, newpolicydb, sizeof policydb);

Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

selinux: consider filesystem subtype in policies

Not considering sub filesystem has the following limitation. Support
for SELinux in FUSE is dependent on the particular userspace
filesystem, which is identified by the subtype. For e.g, GlusterFS,
a FUSE based filesystem supports SELinux (by mounting and processing
FUSE requests in different threads, avoiding the mount time
deadlock), whereas other FUSE based filesystems (identified by a
different subtype) have the mount time deadlock.

By considering the subtype of the filesytem in the SELinux policies,
allows us to specify a filesystem subtype, in the following way:

fs_use_xattr fuse.glusterfs gen_context(system_u:object_r:fs_t,s0);

This way not all FUSE filesystems are put in the same bucket and
subjected to the limitations of the other subtypes.

Signed-off-by: Anand Avati <avati@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

Add SELinux policy capability for always checking packet and peer classes.

Currently the packet class in SELinux is not checked if there are no
SECMARK rules in the security or mangle netfilter tables. Some systems
prefer that packets are always checked, for example, to protect the system
should the netfilter rules fail to load or if the nefilter rules
were maliciously flushed.

Add the always_check_network policy capability which, when enabled, treats
SECMARK as enabled, even if there are no netfilter SECMARK rules and
treats peer labeling as enabled, even if there is no Netlabel or
labeled IPSEC configuration.

Includes definition of "redhat1" SELinux policy capability, which
exists in the SELinux userpace library, to keep ordering correct.

The SELinux userpace portion of this was merged last year, but this kernel
change fell on the floor.

Signed-off-by: Chris PeBenito <cpebenito@tresys.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: pass a superblock to security_fs_use

Rather than passing pointers to memory locations, strings, and other
stuff just give up on the separation and give security_fs_use the
superblock. It just makes the code easier to read (even if not easier to
reuse on some other OS)

Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: change sbsec->behavior to short

We only have 6 options, so char is good enough, but use a short as that
packs nicely. This shrinks the superblock_security_struct just a little
bit.

Signed-off-by: Eric Paris <eparis@redhat.com>

userns: Convert selinux to use kuid and kgid where appropriate

Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

SELinux: avc: remove the useless fields in avc_add_callback

avc_add_callback now just used for registering reset functions
in initcalls, and the callback functions just did reset operations.
So, reducing the arguments to only one event is enough now.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: possible NULL deref in context_struct_to_string

It's possible that the caller passed a NULL for scontext. However if this
is a defered mapping we might still attempt to call *scontext=kstrdup().
This is bad. Instead just return the len.

Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: add default_type statements

Because Fedora shipped userspace based on my development tree we now
have policy version 27 in the wild defining only default user, role, and
range. Thus to add default_type we need a policy.28.

Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: allow default source/target selectors for user/role/range

When new objects are created we have great and flexible rules to
determine the type of the new object. We aren't quite as flexible or
mature when it comes to determining the user, role, and range. This
patch adds a new ability to specify the place a new objects user, role,
and range should come from. For users and roles it can come from either
the source or the target of the operation. aka for files the user can
either come from the source (the running process and todays default) or
it can come from the target (aka the parent directory of the new file)

examples always are done with
directory context: system_u:object_r:mnt_t:s0-s0:c0.c512
process context: unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

[no rule]
unconfined_u:object_r:mnt_t:s0 test_none
[default user source]
unconfined_u:object_r:mnt_t:s0 test_user_source
[default user target]
system_u:object_r:mnt_t:s0 test_user_target
[default role source]
unconfined_u:unconfined_r:mnt_t:s0 test_role_source
[default role target]
unconfined_u:object_r:mnt_t:s0 test_role_target
[default range source low]
unconfined_u:object_r:mnt_t:s0 test_range_source_low
[default range source high]
unconfined_u:object_r:mnt_t:s0:c0.c1023 test_range_source_high
[default range source low-high]
unconfined_u:object_r:mnt_t:s0-s0:c0.c1023 test_range_source_low-high
[default range target low]
unconfined_u:object_r:mnt_t:s0 test_range_target_low
[default range target high]
unconfined_u:object_r:mnt_t:s0:c0.c512 test_range_target_high
[default range target low-high]
unconfined_u:object_r:mnt_t:s0-s0:c0.c512 test_range_target_low-high

Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: sparse fix: fix warnings in netlink code

Fix sparse warnings in SELinux Netlink code.

Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: sparse fix: move selinux_complete_init

Sparse fix: move selinux_complete_init

Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: sparse fix: fix warnings in netlink code

Fix sparse warnings in SELinux Netlink code.

Signed-off-by: James Morris <jmorris@namei.org>

selinux: sparse fix: move selinux_complete_init

Sparse fix: move selinux_complete_init

Signed-off-by: James Morris <jmorris@namei.org>

doc: Update the email address for Paul Moore in various source files

My @hp.com will no longer be valid starting August 5, 2011 so an update is
necessary. My new email address is employer independent so we don't have
to worry about doing this again any time soon.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <jmorris@namei.org>

doc: Update the email address for Paul Moore in various source files

My @hp.com will no longer be valid starting August 5, 2011 so an update is
necessary. My new email address is employer independent so we don't have
to worry about doing this again any time soon.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selinux: don't pass in NULL avd to avc_has_perm_noaudit

Right now security_get_user_sids() will pass in a NULL avd pointer to
avc_has_perm_noaudit(), which then forces that function to have a dummy
entry for that case and just generally test it.

Don't do it. The normal callers all pass a real avd pointer, and this
helper function is incredibly hot. So don't make avc_has_perm_noaudit()
do conditional stuff that isn't needed for the common case.

This also avoids some duplicated stack space.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SELinux: put name based create rules in a hashtable

To shorten the list we need to run if filename trans rules exist for the type
of the given parent directory I put them in a hashtable. Given the policy we
are expecting to use in Fedora this takes the worst case list run from about
5,000 entries to 17.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>

SELinux: skip filename trans rules if ttype does not match parent dir

Right now we walk to filename trans rule list for every inode that is
created. First passes at policy using this facility creates around 5000
filename trans rules. Running a list of 5000 entries every time is a bad
idea. This patch adds a new ebitmap to policy which has a bit set for each
ttype that has at least 1 filename trans rule. Thus when an inode is
created we can quickly determine if any rules exist for this parent
directory type and can skip the list if we know there is definitely no
relevant entry.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>

SELinux: rename filename_compute_type argument to *type instead of *con

filename_compute_type() takes as arguments the numeric value of the type of
the subject and target. It does not take a context. Thus the names are
misleading. Fix the argument names.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>

SELinux: fix comment to state filename_compute_type takes an objname not a qstr

filename_compute_type used to take a qstr, but it now takes just a name.
Fix the comments to indicate it is an objname, not a qstr.

Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: security_read_policy should take a size_t not ssize_t

The len should be an size_t but is a ssize_t. Easy enough fix to silence
build warnings. We have no need for signed-ness.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>

selinux: Fix regression for Xorg

Commit 6f5317e730505d5cbc851c435a2dfe3d5a21d343 introduced a bug in the
handling of userspace object classes that is causing breakage for Xorg
when XSELinux is enabled. Fix the bug by changing map_class() to return
SECCLASS_NULL when the class cannot be mapped to a kernel object class.

Reported-by: "Justin P. Mattock" <justinmattock@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: add type_transition with name extension support for selinuxfs

The attached patch allows /selinux/create takes optional 4th argument
to support TYPE_TRANSITION with name extension for userspace object
managers.
If 4th argument is not supplied, it shall perform as existing kernel.
In fact, the regression test of SE-PostgreSQL works well on the patched
kernel.

Thanks,

Signed-off-by: KaiGai Kohei <kohei.kaigai@eu.nec.com>
[manually verify fuzz was not an issue, and it wasn't: eparis]
Signed-off-by: Eric Paris <eparis@redhat.com>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

selinux: Fix regression for Xorg

Commit 6f5317e730505d5cbc851c435a2dfe3d5a21d343 introduced a bug in the
handling of userspace object classes that is causing breakage for Xorg
when XSELinux is enabled. Fix the bug by changing map_class() to return
SECCLASS_NULL when the class cannot be mapped to a kernel object class.

Reported-by: "Justin P. Mattock" <justinmattock@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: Compute role in newcontext for all classes

Apply role_transition rules for all kinds of classes.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: Socket retains creator role and MLS attribute

The socket SID would be computed on creation and no longer inherit
its creator's SID by default. Socket may have a different type but
needs to retain the creator's role and MLS attribute in order not
to break labeled networking and network access control.

The kernel value for a class would be used to determine if the class
if one of socket classes. If security_compute_sid is called from
userspace the policy value for a class would be mapped to the relevant
kernel value first.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

SELinux: Use dentry name in new object labeling

Currently SELinux has rules which label new objects according to 3 criteria.
The label of the process creating the object, the label of the parent
directory, and the type of object (reg, dir, char, block, etc.) This patch
adds a 4th criteria, the dentry name, thus we can distinguish between
creating a file in an etc_t directory called shadow and one called motd.

There is no file globbing, regex parsing, or anything mystical. Either the
policy exactly (strcmp) matches the dentry name of the object or it doesn't.
This patch has no changes from today if policy does not implement the new
rules.

Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: convert part of the sym_val_to_name array to use flex_array

The sym_val_to_name type array can be quite large as it grows linearly with
the number of types. With known policies having over 5k types these
allocations are growing large enough that they are likely to fail. Convert
those to flex_array so no allocation is larger than PAGE_SIZE

Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: convert type_val_to_struct to flex_array

In rawhide type_val_to_struct will allocate 26848 bytes, an order 3
allocations. While this hasn't been seen to fail it isn't outside the
realm of possibiliy on systems with severe memory fragmentation. Convert
to flex_array so no allocation will ever be bigger than PAGE_SIZE.

Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: rework security_netlbl_secattr_to_sid

security_netlbl_secattr_to_sid is difficult to follow, especially the
return codes. Try to make the function obvious.

Signed-off-by: Eric Paris <eparis@redhat.com>

SELinux: standardize return code handling in selinuxfs.c

selinuxfs.c has lots of different standards on how to handle return paths on
error. For the most part transition to

rc=errno
if (failure)
goto out;
[...]
out:
cleanup()
return rc;

Instead of doing cleanup mid function, or having multiple returns or other
options. This doesn't do that for every function, but most of the complex
functions which have cleanup routines on error.

Signed-off-by: Eric Paris <eparis@redhat.com>

selinux: include vmalloc.h for vmalloc_user

Include vmalloc.h for vmalloc_user (fixes ppc build warning).
Acked-by: Eric Paris <eparis@redhat.com>

Signed-off-by: James Morris <jmorris@namei.org>

selinux: implement mmap on /selinux/policy

/selinux/policy allows a user to copy the policy back out of the kernel.
This patch allows userspace to actually mmap that file and use it directly.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: allow userspace to read policy back out of the kernel

There is interest in being able to see what the actual policy is that was
loaded into the kernel. The patch creates a new selinuxfs file
/selinux/policy which can be read by userspace. The actual policy that is
loaded into the kernel will be written back out to userspace.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

security: secid_to_secctx returns len when data is NULL

With the (long ago) interface change to have the secid_to_secctx functions
do the string allocation instead of having the caller do the allocation we
lost the ability to query the security server for the length of the
upcoming string. The SECMARK code would like to allocate a netlink skb
with enough length to hold the string but it is just too unclean to do the
string allocation twice or to do the allocation the first time and hold
onto the string and slen. This patch adds the ability to call
security_secid_to_secctx() with a NULL data pointer and it will just set
the slen pointer.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: fast status update interface (/selinux/status)

This patch provides a new /selinux/status entry which allows applications
read-only mmap(2).
This region reflects selinux_kernel_status structure in kernel space.
struct selinux_kernel_status
{
u32 length; /* length of this structure */
u32 sequence; /* sequence number of seqlock logic */
u32 enforcing; /* current setting of enforcing mode */
u32 policyload; /* times of policy reloaded */
u32 deny_unknown; /* current setting of deny_unknown */
};

When userspace object manager caches access control decisions provided
by SELinux, it needs to invalidate the cache on policy reload and setenforce
to keep consistency.
However, the applications need to check the kernel state for each accesses
on userspace avc, or launch a background worker process.
In heuristic, frequency of invalidation is much less than frequency of
making access control decision, so it is annoying to invoke a system call
to check we don't need to invalidate the userspace cache.
If we can use a background worker thread, it allows to receive invalidation
messages from the kernel. But it requires us an invasive coding toward the
base application in some cases; E.g, when we provide a feature performing
with SELinux as a plugin module, it is unwelcome manner to launch its own
worker thread from the module.

If we could map /selinux/status to process memory space, application can
know updates of selinux status; policy reload or setenforce.

A typical application checks selinux_kernel_status::sequence when it tries
to reference userspace avc. If it was changed from the last time when it
checked userspace avc, it means something was updated in the kernel space.
Then, the application can reset userspace avc or update current enforcing
mode, without any system call invocations.
This sequence number is updated according to the seqlock logic, so we need
to wait for a while if it is odd number.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Eric Paris <eparis@redhat.com>
--
security/selinux/include/security.h | 21 ++++++
security/selinux/selinuxfs.c | 56 +++++++++++++++
security/selinux/ss/Makefile | 2 +-
security/selinux/ss/services.c | 3 +
security/selinux/ss/status.c | 129 +++++++++++++++++++++++++++++++++++
5 files changed, 210 insertions(+), 1 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>

selinux: convert the policy type_attr_map to flex_array

Current selinux policy can have over 3000 types. The type_attr_map in
policy is an array sized by the number of types times sizeof(struct ebitmap)
(12 on x86_64). Basic math tells us the array is going to be of length
3000 x 12 = 36,000 bytes. The largest 'safe' allocation on a long running
system is 16k. Most of the time a 32k allocation will work. But on long
running systems a 64k allocation (what we need) can fail quite regularly.
In order to deal with this I am converting the type_attr_map to use
flex_arrays. Let the library code deal with breaking this into PAGE_SIZE
pieces.

-v2
rework some of the if(!obj) BUG() to be BUG_ON(!obj)
drop flex_array_put() calls and just use a _get() object directly

-v3
make apply to James' tree (drop the policydb_write changes)

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: return error codes on policy load failure

policy load failure always return EINVAL even if the failure was for some
other reason (usually ENOMEM). This patch passes error codes back up the
stack where they will make their way to userspace. This might help in
debugging future problems with policy load.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

Security: Fix coding style in security/

Fix coding style in security/

Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: libsepol: remove dead code in check_avtab_hierarchy_callback()

This patch revert the commit of 7d52a155e38d5a165759dbbee656455861bf7801
which removed a part of type_attribute_bounds_av as a dead code.
However, at that time, we didn't find out the target side boundary allows
to handle some of pseudo /proc/<pid>/* entries with its process's security
context well.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

--
security/selinux/ss/services.c | 43 ++++++++++++++++++++++++++++++++++++---
1 files changed, 39 insertions(+), 4 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>

security: fix a couple of sparse warnings

Fix a couple of sparse warnings for callers of
context_struct_to_string, which takes a *u32, not an *int.

These cases are harmless as the values are not used.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: KaiGai Kohei <kaigai@ak.jp.nec.com>

selinux: allow MLS->non-MLS and vice versa upon policy reload

Allow runtime switching between different policy types (e.g. from a MLS/MCS
policy to a non-MLS/non-MCS policy or viceversa).

Signed-off-by: Guido Trentalancia <guido@trentalancia.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: load the initial SIDs upon every policy load

Always load the initial SIDs, even in the case of a policy
reload and not just at the initial policy load. This comes
particularly handy after the introduction of a recent
patch for enabling runtime switching between different
policy types, although this patch is in theory independent
from that feature.

Signed-off-by: Guido Trentalancia <guido@trentalancia.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: remove dead code in type_attribute_bounds_av()

This patch removes dead code in type_attribute_bounds_av().

Due to the historical reason, the type boundary feature is delivered
from hierarchical types in libsepol, it has supported boundary features
both of subject type (domain; in most cases) and target type.

However, we don't have any actual use cases in bounded target types,
and it tended to make conceptual confusion.
So, this patch removes the dead code to apply boundary checks on the
target types. I makes clear the TYPEBOUNDS restricts privileges of
a certain domain bounded to any other domain.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

--
security/selinux/ss/services.c | 43 +++------------------------------------
1 files changed, 4 insertions(+), 39 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>

selinux: change the handling of unknown classes

If allow_unknown==deny, SELinux treats an undefined kernel security
class as an error condition rather than as a typical permission denial
and thus does not allow permissions on undefined classes even when in
permissive mode. Change the SELinux logic so that this case is handled
as a typical permission denial, subject to the usual permissive mode and
permissive domain handling.

Also drop the 'requested' argument from security_compute_av() and
helpers as it is a legacy of the original security server interface and
is unused.

Changes:
- Handle permissive domains consistently by moving up the test for a
permissive domain.
- Make security_compute_av_user() consistent with security_compute_av();
the only difference now is that security_compute_av() performs mapping
between the kernel-private class and permission indices and the policy
values. In the userspace case, this mapping is handled by libselinux.
- Moved avd_init inside the policy lock.

Based in part on a patch by Paul Moore <paul.moore@hp.com>.

Reported-by: Andrew Worsley <amworsley@gmail.com>
Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/selinux/ss: correct size computation

The size argument to kcalloc should be the size of desired structure,
not the pointer to it.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@expression@
expression *x;
@@

x =
<+...
-sizeof(x)
+sizeof(*x)
...+>// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

tree-wide: fix assorted typos all over the place

That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

SELinux: print denials for buggy kernel with unknown perms

Historically we've seen cases where permissions are requested for classes
where they do not exist. In particular we have seen CIFS forget to set
i_mode to indicate it is a directory so when we later check something like
remove_name we have problems since it wasn't defined in tclass file. This
used to result in a avc which included the permission 0x2000 or something.
Currently the kernel will deny the operations (good thing) but will not
print ANY information (bad thing). First the auditdeny field is no
extended to include unknown permissions. After that is fixed the logic in
avc_dump_query to output this information isn't right since it will remove
the permission from the av and print the phrase "<NULL>". This takes us
back to the behavior before the classmap rewrite.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: fix locking issue introduced with c6d3aaa4e35c71a3

Ensure that we release the policy read lock on all exit paths from
security_compute_av.

Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: drop remapping of netlink classes

Drop remapping of netlink classes and bypass of permission checking
based on netlink message type for policy version < 18. This removes
compatibility code introduced when the original single netlink
security class used for all netlink sockets was split into
finer-grained netlink classes based on netlink protocol and when
permission checking was added based on netlink message type in Linux
2.6.8. The only known distribution that shipped with SELinux and
policy < 18 was Fedora Core 2, which was EOL'd on 2005-04-11.

Given that the remapping code was never updated to address the
addition of newer netlink classes, that the corresponding userland
support was dropped in 2005, and that the assumptions made by the
remapping code about the fixed ordering among netlink classes in the
policy may be violated in the future due to the dynamic class/perm
discovery support, we should drop this compatibility code now.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: dynamic class/perm discovery

Modify SELinux to dynamically discover class and permission values
upon policy load, based on the dynamic object class/perm discovery
logic from libselinux. A mapping is created between kernel-private
class and permission indices used outside the security server and the
policy values used within the security server.

The mappings are only applied upon kernel-internal computations;
similar mappings for the private indices of userspace object managers
is handled on a per-object manager basis by the userspace AVC. The
interfaces for compute_av and transition_sid are split for kernel
vs. userspace; the userspace functions are distinguished by a _user
suffix.

The kernel-private class indices are no longer tied to the policy
values and thus do not need to skip indices for userspace classes;
thus the kernel class index values are compressed. The flask.h
definitions were regenerated by deleting the userspace classes from
refpolicy's definitions and then regenerating the headers. Going
forward, we can just maintain the flask.h, av_permissions.h, and
classmap.h definitions separately from policy as they are no longer
tied to the policy values. The next patch introduces a utility to
automate generation of flask.h and av_permissions.h from the
classmap.h definitions.

The older kernel class and permission string tables are removed and
replaced by a single security class mapping table that is walked at
policy load to generate the mapping. The old kernel class validation
logic is completely replaced by the mapping logic.

The handle unknown logic is reworked. reject_unknown=1 is handled
when the mappings are computed at policy load time, similar to the old
handling by the class validation logic. allow_unknown=1 is handled
when computing and mapping decisions - if the permission was not able
to be mapped (i.e. undefined, mapped to zero), then it is
automatically added to the allowed vector. If the class was not able
to be mapped (i.e. undefined, mapped to zero), then all permissions
are allowed for it if allow_unknown=1.

avc_audit leverages the new security class mapping table to lookup the
class and permission names from the kernel-private indices.

The mdp program is updated to use the new table when generating the
class definitions and allow rules for a minimal boot policy for the
kernel. It should be noted that this policy will not include any
userspace classes, nor will its policy index values for the kernel
classes correspond with the ones in refpolicy (they will instead match
the kernel-private indices).

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

Add audit messages on type boundary violations

The attached patch adds support to generate audit messages on two cases.

The first one is a case when a multi-thread process tries to switch its
performing security context using setcon(3), but new security context is
not bounded by the old one.

type=SELINUX_ERR msg=audit(1245311998.599:17): \
op=security_bounded_transition result=denied \
oldcontext=system_u:system_r:httpd_t:s0 \
newcontext=system_u:system_r:guest_webapp_t:s0

The other one is a case when security_compute_av() masked any permissions
due to the type boundary violation.

type=SELINUX_ERR msg=audit(1245312836.035:32): \
op=security_compute_av reason=bounds \
scontext=system_u:object_r:user_webapp_t:s0 \
tcontext=system_u:object_r:shadow_t:s0:c0 \
tclass=file perms=getattr,open

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

cleanup in ss/services.c

It is a cleanup patch to cut down a line within 80 columns.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
--
security/selinux/ss/services.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>

Permissive domain in userspace object manager

This patch enables applications to handle permissive domain correctly.

Since the v2.6.26 kernel, SELinux has supported an idea of permissive
domain which allows certain processes to work as if permissive mode,
even if the global setting is enforcing mode.
However, we don't have an application program interface to inform
what domains are permissive one, and what domains are not.
It means applications focuses on SELinux (XACE/SELinux, SE-PostgreSQL
and so on) cannot handle permissive domain correctly.

This patch add the sixth field (flags) on the reply of the /selinux/access
interface which is used to make an access control decision from userspace.
If the first bit of the flags field is positive, it means the required
access control decision is on permissive domain, so application should
allow any required actions, as the kernel doing.

This patch also has a side benefit. The av_decision.flags is set at
context_struct_compute_av(). It enables to check required permissions
without read_lock(&policy_rwlock).

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
--
security/selinux/avc.c | 2 +-
security/selinux/include/security.h | 4 +++-
security/selinux/selinuxfs.c | 4 ++--
security/selinux/ss/services.c | 30 +++++-------------------------
4 files changed, 11 insertions(+), 29 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: remove unused av.decided field

It appears there was an intention to have the security server only decide
certain permissions and leave other for later as some sort of a portential
performance win. We are currently always deciding all 32 bits of
permissions and this is a useless couple of branches and wasted space.
This patch completely drops the av.decided concept.

This in a 17% reduction in the time spent in avc_has_perm_noaudit
based on oprofile sampling of a tbench benchmark.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

audit: validate comparison operations, store them in sane form

Don't store the field->op in the messy (and very inconvenient for e.g.
audit_comparator()) form; translate to dense set of values and do full
validation of userland-submitted value while we are at it.

->audit_init_rule() and ->audit_match_rule() get new values now; in-tree
instances updated.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

netlabel: Changes to the NetLabel security attributes to allow LSMs to pass full contexts

This patch provides support for including the LSM's secid in addition to
the LSM's MLS information in the NetLabel security attributes structure.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>

selinux: Fix a problem in security_netlbl_sid_to_secattr()

Currently when SELinux fails to allocate memory in
security_netlbl_sid_to_secattr() the NetLabel LSM domain field is set to
NULL which triggers the default NetLabel LSM domain mapping which may not
always be the desired mapping. This patch fixes this by returning an error
when the kernel is unable to allocate memory. This could result in more
failures on a system with heavy memory pressure but it is the "correct"
thing to do.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>

selinux: Fix an uninitialized variable BUG/panic in selinux_secattr_to_sid()

At some point during the 2.6.27 development cycle two new fields were added
to the SELinux context structure, a string pointer and a length field. The
code in selinux_secattr_to_sid() was not modified and as a result these two
fields were left uninitialized which could result in erratic behavior,
including kernel panics, when NetLabel is used. This patch fixes the
problem by fully initializing the context in selinux_secattr_to_sid() before
use and reducing the level of direct context manipulation done to help
prevent future problems.

Please apply this to the 2.6.27-rcX release stream.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: Fix an uninitialized variable BUG/panic in selinux_secattr_to_sid()

At some point during the 2.6.27 development cycle two new fields were added
to the SELinux context structure, a string pointer and a length field. The
code in selinux_secattr_to_sid() was not modified and as a result these two
fields were left uninitialized which could result in erratic behavior,
including kernel panics, when NetLabel is used. This patch fixes the
problem by fully initializing the context in selinux_secattr_to_sid() before
use and reducing the level of direct context manipulation done to help
prevent future problems.

Please apply this to the 2.6.27-rcX release stream.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: memory leak in security_context_to_sid_core

Fix a bug and a philosophical decision about who handles errors.

security_context_to_sid_core() was leaking a context in the common case.
This was causing problems on fedora systems which recently have started
making extensive use of this function.

In discussion it was decided that if string_to_context_struct() had an
error it was its own responsibility to clean up any mess it created
along the way.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: add boundary support and thread context assignment

The purpose of this patch is to assign per-thread security context
under a constraint. It enables multi-threaded server application
to kick a request handler with its fair security context, and
helps some of userspace object managers to handle user's request.

When we assign a per-thread security context, it must not have wider
permissions than the original one. Because a multi-threaded process
shares a single local memory, an arbitary per-thread security context
also means another thread can easily refer violated information.

The constraint on a per-thread security context requires a new domain
has to be equal or weaker than its original one, when it tries to assign
a per-thread security context.

Bounds relationship between two types is a way to ensure a domain can
never have wider permission than its bounds. We can define it in two
explicit or implicit ways.

The first way is using new TYPEBOUNDS statement. It enables to define
a boundary of types explicitly. The other one expand the concept of
existing named based hierarchy. If we defines a type with "." separated
name like "httpd_t.php", toolchain implicitly set its bounds on "httpd_t".

This feature requires a new policy version.
The 24th version (POLICYDB_VERSION_BOUNDARY) enables to ship them into
kernel space, and the following patch enables to handle it.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: Unify for- and while-loop style

Replace "thing != NULL" comparisons with just "thing" to make
the code look more uniform (mixed styles were used even in the
same source file).

Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

Revert "SELinux: allow fstype unknown to policy to use xattrs if present"

This reverts commit 811f3799279e567aa354c649ce22688d949ac7a9.

From Eric Paris:

"Please drop this patch for now. It deadlocks on ntfs-3g. I need to
rework it to handle fuse filesystems better. (casey was right)"

SELinux: allow fstype unknown to policy to use xattrs if present

Currently if a FS is mounted for which SELinux policy does not define an
fs_use_* that FS will either be genfs labeled or not labeled at all.
This decision is based on the existence of a genfscon rule in policy and
is irrespective of the capabilities of the filesystem itself. This
patch allows the kernel to check if the filesystem supports security
xattrs and if so will use those if there is no fs_use_* rule in policy.
An fstype with a no fs_use_* rule but with a genfs rule will use xattrs
if available and will follow the genfs rule.

This can be particularly interesting for things like ecryptfs which
actually overlays a real underlying FS. If we define excryptfs in
policy to use xattrs we will likely get this wrong at times, so with
this path we just don't need to define it!

Overlay ecryptfs on top of NFS with no xattr support:
SELinux: initialized (dev ecryptfs, type ecryptfs), uses genfs_contexts
Overlay ecryptfs on top of ext4 with xattr support:
SELinux: initialized (dev ecryptfs, type ecryptfs), uses xattr

It is also useful as the kernel adds new FS we don't need to add them in
policy if they support xattrs and that is how we want to handle them.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: more user friendly unknown handling printk

I've gotten complaints and reports about people not understanding the
meaning of the current unknown class/perm handling the kernel emits on
every policy load. Hopefully this will make make it clear to everyone
the meaning of the message and won't waste a printk the user won't care
about anyway on systems where the kernel and the policy agree on
everything.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: change handling of invalid classes (Was: Re: 2.6.26-rc5-mm1 selinux whine)

On Mon, 2008-06-09 at 01:24 -0700, Andrew Morton wrote:
> Getting a few of these with FC5:
>
> SELinux: context_struct_compute_av: unrecognized class 69
> SELinux: context_struct_compute_av: unrecognized class 69
>
> one came out when I logged in.
>
> No other symptoms, yet.

Change handling of invalid classes by SELinux, reporting class values
unknown to the kernel as errors (w/ ratelimit applied) and handling
class values unknown to policy as normal denials.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: drop load_mutex in security_load_policy

We used to protect against races of policy load in security_load_policy
by using the load_mutex. Since then we have added a new mutex,
sel_mutex, in sel_write_load() which is always held across all calls to
security_load_policy we are covered and can safely just drop this one.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: fix off by 1 reference of class_to_string in context_struct_compute_av

The class_to_string array is referenced by tclass. My code mistakenly
was using tclass - 1. If the proceeding class is a userspace class
rather than kernel class this may cause a denial/EINVAL even if unknown
handling is set to allow. The bug shouldn't be allowing excess
privileges since those are given based on the contents of another array
which should be correctly referenced.

At this point in time its pretty unlikely this is going to cause
problems. The most recently added kernel classes which could be
affected are association, dccp_socket, and peer. Its pretty unlikely
any policy with handle_unknown=allow doesn't have association and
dccp_socket undefined (they've been around longer than unknown handling)
and peer is conditionalized on a policy cap which should only be defined
if that class exists in policy.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: open code load_mutex

Open code load_mutex as suggested by Andrew Morton.

Signed-off-by: James Morris <jmorris@namei.org>

SELinux: open code policy_rwlock

Open code policy_rwlock, as suggested by Andrew Morton.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

SELinux: keep the code clean formating and syntax

Formatting and syntax changes

whitespace, tabs to spaces, trailing space
put open { on same line as struct def
remove unneeded {} after if statements
change printk("Lu") to printk("llu")
convert asm/uaccess.h to linux/uaacess.h includes
remove unnecessary asm/bug.h includes
convert all users of simple_strtol to strict_strtol

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: fix sleeping allocation in security_context_to_sid

Fix a sleeping function called from invalid context bug by moving allocation
to the callers prior to taking the policy rdlock.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: support deferred mapping of contexts

Introduce SELinux support for deferred mapping of security contexts in
the SID table upon policy reload, and use this support for inode
security contexts when the context is not yet valid under the current
policy. Only processes with CAP_MAC_ADMIN + mac_admin permission in
policy can set undefined security contexts on inodes. Inodes with
such undefined contexts are treated as having the unlabeled context
until the context becomes valid upon a policy reload that defines the
context. Context invalidation upon policy reload also uses this
support to save the context information in the SID table and later
recover it upon a subsequent policy reload that defines the context
again.

This support is to enable package managers and similar programs to set
down file contexts unknown to the system policy at the time the file
is created in order to better support placing loadable policy modules
in packages and to support build systems that need to create images of
different distro releases with different policies w/o requiring all of
the contexts to be defined or legal in the build host policy.

With this patch applied, the following sequence is possible, although
in practice it is recommended that this permission only be allowed to
specific program domains such as the package manager.

# rmdir baz
# rm bar
# touch bar
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument
# cat setundefined.te
policy_module(setundefined, 1.0)
require {
type unconfined_t;
type unlabeled_t;
}
files_type(unlabeled_t)
allow unconfined_t self:capability2 mac_admin;
# make -f /usr/share/selinux/devel/Makefile setundefined.pp
# semodule -i setundefined.pp
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
# mkdir -Z system_u:object_r:foo_exec_t baz
# ls -Zd bar baz
-rw-r--r-- root root system_u:object_r:unlabeled_t bar
drwxr-xr-x root root system_u:object_r:unlabeled_t baz
# cat foo.te
policy_module(foo, 1.0)
type foo_exec_t;
files_type(foo_exec_t)
# make -f /usr/share/selinux/devel/Makefile foo.pp
# semodule -i foo.pp # defines foo_exec_t
# ls -Zd bar baz
-rw-r--r-- root root user_u:object_r:foo_exec_t bar
drwxr-xr-x root root system_u:object_r:foo_exec_t baz
# semodule -r foo
# ls -Zd bar baz
-rw-r--r-- root root system_u:object_r:unlabeled_t bar
drwxr-xr-x root root system_u:object_r:unlabeled_t baz
# semodule -i foo.pp
# ls -Zd bar baz
-rw-r--r-- root root user_u:object_r:foo_exec_t bar
drwxr-xr-x root root system_u:object_r:foo_exec_t baz
# semodule -r setundefined foo
# chcon -t foo_exec_t bar # no longer defined and not allowed
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# rmdir baz
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

Security: Make secctx_to_secid() take const secdata

Make secctx_to_secid() take constant secdata.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>

Security: Make secctx_to_secid() take const secdata

Make secctx_to_secid() take constant secdata.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xattr: add missing consts to function arguments

Add missing consts to xattr function arguments.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SELinux: clean up printks

Make sure all printk start with KERN_*
Make sure all printk end with \n
Make sure all printk have the word 'selinux' in them
Change "function name" to "%s", __func__ (found 2 wrong)

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: services.c whitespace, syntax, and static declaraction cleanups

This patch changes services.c to fix whitespace and syntax issues. Things that
are fixed may include (does not not have to include)

whitespace at end of lines
spaces followed by tabs
spaces used instead of tabs
spacing around parenthesis
locateion of { around struct and else clauses
location of * in pointer declarations
removal of initialization of static data to keep it in the right section
useless {} in if statemetns
useless checking for NULL before kfree
fixing of the indentation depth of switch statements
and any number of other things I forgot to mention

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: use new audit hooks, remove redundant exports

Setup the new Audit LSM hooks for SELinux.
Remove the now redundant exported SELinux Audit interface.

Audit: Export 'audit_krule' and 'audit_field' to the public
since their internals are needed by the implementation of the
new LSM hook 'audit_rule_known'.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>

SELinux: Add network port SID cache

Much like we added a network node cache, this patch adds a network port
cache. The design is taken almost completely from the network node cache
which in turn was taken from the network interface cache. The basic idea is
to cache entries in a hash table based on protocol/port information. The
hash function only takes the port number into account since the number of
different protocols in use at any one time is expected to be relatively
small.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux/ss/services.c should #include <linux/selinux.h>

Every file should include the headers containing the externs for its global
code.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: introduce permissive types

Introduce the concept of a permissive type. A new ebitmap is introduced to
the policy database which indicates if a given type has the permissive bit
set or not. This bit is tested for the scontext of any denial. The bit is
meaningless on types which only appear as the target of a decision and never
the source. A domain running with a permissive type will be allowed to
perform any action similarly to when the system is globally set permissive.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

security: replace remaining __FUNCTION__ occurrences

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: create new open permission

Adds a new open permission inside SELinux when 'opening' a file. The idea
is that opening a file and reading/writing to that file are not the same
thing. Its different if a program had its stdout redirected to /tmp/output
than if the program tried to directly open /tmp/output. This should allow
policy writers to more liberally give read/write permissions across the
policy while still blocking many design and programing flaws SELinux is so
good at catching today.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: unify printk messages

Replace "security:" prefixes in printk messages with "SELinux"
to help users identify the source of the messages. Also fix a
couple of minor formatting issues.

Signed-off-by: James Morris <jmorris@namei.org>

NetLabel: Allow passing the LSM domain as a shared pointer

Smack doesn't have the need to create a private copy of the LSM "domain" when
setting NetLabel security attributes like SELinux, however, the current
NetLabel code requires a private copy of the LSM "domain". This patches fixes
that by letting the LSM determine how it wants to pass the domain value.

* NETLBL_SECATTR_DOMAIN_CPY
The current behavior, NetLabel assumes that the domain value is a copy and
frees it when done

* NETLBL_SECATTR_DOMAIN
New, Smack-friendly behavior, NetLabel assumes that the domain value is a
reference to a string managed by the LSM and does not free it when done

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

SELinux: more GFP_NOFS fixups to prevent selinux from re-entering the fs code

More cases where SELinux must not re-enter the fs code. Called from the
d_instantiate security hook.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: Remove security_get_policycaps()

The security_get_policycaps() functions has a couple of bugs in it and it
isn't currently used by any in-tree code, so get rid of it and all of it's
bugginess.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@localhost.localdomain>

[AUDIT] add session id to audit messages

In order to correlate audit records to an individual login add a session
id. This is incremented every time a user logs in and is included in
almost all messages which currently output the auid. The field is
labeled ses= or oses=

Signed-off-by: Eric Paris <eparis@redhat.com>

[PATCH] switch audit_get_loginuid() to task_struct *

all callers pass something->audit_context

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[SELinux]: Fix double free in selinux_netlbl_sock_setsid()

As pointed out by Adrian Bunk, commit
45c950e0f839fded922ebc0bfd59b1081cc71b70 ("fix memory leak in netlabel
code") caused a double-free when security_netlbl_sid_to_secattr()
fails. This patch fixes this by removing the netlbl_secattr_destroy()
call from that function since we are already releasing the secattr
memory in selinux_netlbl_sock_setsid().

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

SELinux: Allow NetLabel to directly cache SIDs

Now that the SELinux NetLabel "base SID" is always the netmsg initial SID we
can do a big optimization - caching the SID and not just the MLS attributes.
This not only saves a lot of per-packet memory allocations and copies but it
has a nice side effect of removing a chunk of code.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: Better integration between peer labeling subsystems

Rework the handling of network peer labels so that the different peer labeling
subsystems work better together. This includes moving both subsystems to a
single "peer" object class which involves not only changes to the permission
checks but an improved method of consolidating multiple packet peer labels.
As part of this work the inbound packet permission check code has been heavily
modified to handle both the old and new behavior in as sane a fashion as
possible.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: Add a capabilities bitmap to SELinux policy version 22

Add a new policy capabilities bitmap to SELinux policy version 22. This bitmap
will enable the security server to query the policy to determine which features
it supports.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: Convert the netif code to use ifindex values

The current SELinux netif code requires the caller have a valid net_device
struct pointer to lookup network interface information. However, we don't
always have a valid net_device pointer so convert the netif code to use
the ifindex values we always have as part of the sk_buff. This patch also
removes the default message SID from the network interface record, it is
not being used and therefore is "dead code".

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

NetLabel: Add secid token support to the NetLabel secattr struct

This patch adds support to the NetLabel LSM secattr struct for a secid token
and a type field, paving the way for full LSM/SELinux context support and
"static" or "fallback" labels. In addition, this patch adds a fair amount
of documentation to the core NetLabel structures used as part of the
NetLabel kernel API.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: fix labeling of /proc/net inodes

The proc net rewrite had a side effect on selinux, leading it to mislabel
the /proc/net inodes, thereby leading to incorrect denials. Fix
security_genfs_sid to ignore extra leading / characters in the path supplied
by selinux_proc_get_sid since we now get "//net/..." rather than "/net/...".

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: fix memory leak in netlabel code

Fix a memory leak in security_netlbl_sid_to_secattr() as reported here:
* https://bugzilla.redhat.com/show_bug.cgi?id=352281

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: improve performance when AVC misses.

* We add ebitmap_for_each_positive_bit() which enables to walk on
any positive bit on the given ebitmap, to improve its performance
using common bit-operations defined in linux/bitops.h.
In the previous version, this logic was implemented using a combination
of ebitmap_for_each_bit() and ebitmap_node_get_bit(), but is was worse
in performance aspect.
This logic is most frequestly used to compute a new AVC entry,
so this patch can improve SELinux performance when AVC misses are happen.
* struct ebitmap_node is redefined as an array of "unsigned long", to get
suitable for using find_next_bit() which is fasted than iteration of
shift and logical operation, and to maximize memory usage allocated
from general purpose slab.
* Any ebitmap_for_each_bit() are repleced by the new implementation
in ss/service.c and ss/mls.c. Some of related implementation are
changed, however, there is no incompatibility with the previous
version.
* The width of any new line are less or equal than 80-chars.

The following benchmark shows the effect of this patch, when we
access many files which have different security context one after
another. The number is more than /selinux/avc/cache_threshold, so
any access always causes AVC misses.

selinux-2.6 selinux-2.6-ebitmap
AVG: 22.763 [s] 8.750 [s]
STD: 0.265 0.019
------------------------------------------
1st: 22.558 [s] 8.786 [s]
2nd: 22.458 [s] 8.750 [s]
3rd: 22.478 [s] 8.754 [s]
4th: 22.724 [s] 8.745 [s]
5th: 22.918 [s] 8.748 [s]
6th: 22.905 [s] 8.764 [s]
7th: 23.238 [s] 8.726 [s]
8th: 22.822 [s] 8.729 [s]

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: policy selectable handling of unknown classes and perms

Allow policy to select, in much the same way as it selects MLS support, how
the kernel should handle access decisions which contain either unknown
classes or unknown permissions in known classes. The three choices for the
policy flags are

0 - Deny unknown security access. (default)
2 - reject loading policy if it does not contain all definitions
4 - allow unknown security access

The policy's choice is exported through 2 booleans in
selinuxfs. /selinux/deny_unknown and /selinux/reject_unknown.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: correct error code in selinux_audit_rule_init

Corrects an error code so that it is valid to pass to userspace.

Signed-off-by: Steve Grubb <linux_4ever@yahoo.com>
Signed-off-by: James Morris <jmorris@halo.namei>

Typo fixes errror -> error

Typo fixes errror -> error

Signed-off-by: Gabriel Craciunescu <nix.or.die@googlemail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SELinux: fix memory leak in security_netlbl_cache_add()

Fix memory leak in security_netlbl_cache_add()
Note: The Coverity checker gets credit for spotting this one.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

SELinux: allow preemption between transition permission checks

In security_get_user_sids, move the transition permission checks
outside of the section holding the policy rdlock, and use the AVC to
perform the checks, calling cond_resched after each one. These
changes should allow preemption between the individual checks and
enable caching of the results. It may however increase the overall
time spent in the function in some cases, particularly in the cache
miss case.

The long term fix will be to take much of this logic to userspace by
exporting additional state via selinuxfs, and ultimately deprecating
and eliminating this interface from the kernel.

Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: add support for querying object classes and permissions from the running policy

Add support to the SELinux security server for obtaining a list of classes,
and for obtaining a list of permissions for a specified class.

Signed-off-by: Christopher J. PeBenito <cpebenito@tresys.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: preserve boolean values across policy reloads

At present, the userland policy loading code has to go through contortions to preserve
boolean values across policy reloads, and cannot do so atomically.
As this is what we always want to do for reloads, let the kernel preserve them instead.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Karl MacMillan <kmacmillan@mentalrootkit.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: export initial SID contexts via selinuxfs

Make the initial SID contexts accessible to userspace via selinuxfs.
An initial use of this support will be to make the unlabeled context
available to libselinux for use for invalidated userspace SIDs.

Signed-off-by: James Carter <jwcart2@tycho.nsa.gov>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: remove userland security class and permission definitions

Remove userland security class and permission definitions from the kernel
as the kernel only needs to use and validate its own class and permission
definitions and userland definitions may change.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: move security_skb_extlbl_sid() out of the security server

As suggested, move the security_skb_extlbl_sid() function out of the security
server and into the SELinux hooks file.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: rename selinux_netlabel.h to netlabel.h

In the beginning I named the file selinux_netlabel.h to avoid potential
namespace colisions. However, over time I have realized that there are several
other similar cases of multiple header files with the same name so I'm changing
the name to something which better fits with existing naming conventions.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: extract the NetLabel SELinux support from the security server

Up until this patch the functions which have provided NetLabel support to
SELinux have been integrated into the SELinux security server, which for
various reasons is not really ideal. This patch makes an effort to extract as
much of the NetLabel support from the security server as possibile and move it
into it's own file within the SELinux directory structure.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

Always initialize scontext and scontext_len

Always initialize *scontext and *scontext_len in security_sid_to_context.

(via http://lkml.org/lkml/2007/2/23/135)

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

[SELINUX]: Fix 2.6.20-rc6 build when no xfrm

This patch is an incremental fix to the flow_cache_genid
patch for selinux that breaks the build of 2.6.20-rc6 when
xfrm is not configured.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[SELINUX]: increment flow cache genid

Currently, old flow cache entries remain valid even after
a reload of SELinux policy.

This patch increments the flow cache generation id
on policy (re)loads so that flow cache entries are
revalidated as needed.

Thanks to Herbet Xu for pointing this out. See:
http://marc.theaimsgroup.com/?l=linux-netdev&m=116841378704536&w=2

There's also a general issue as well as a solution proposed
by David Miller for when flow_cache_genid wraps. I might be
submitting a separate patch for that later.

I request that this be applied to 2.6.20 since it's
a security relevant fix.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

NetLabel: correct locking in selinux_netlbl_socket_setsid()

The spinlock protecting the update of the "sksec->nlbl_state" variable is not
currently softirq safe which can lead to problems. This patch fixes this by
changing the spin_{un}lock() functions into spin_{un}lock_bh() functions.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

selinux: Delete mls_copy_context

This deletes mls_copy_context() in favor of mls_context_cpy() and
replaces mls_scopy_context() with mls_context_cpy_low().

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

[PATCH] selinux: fix selinux_netlbl_inode_permission() locking

do not call a sleeping lock API in an RCU read section.
lock_sock_nested can sleep, its BH counterpart doesn't.
selinux_netlbl_inode_permission() needs to use the BH counterpart
unconditionally.

Compile tested.

From: Ingo Molnar <mingo@elte.hu>

added BH disabling, because this function can be called from non-atomic
contexts too, so a naked bh_lock_sock() would be deadlock-prone.

Boot-tested the resulting kernel.

Signed-off-by: Parag Warudkar <paragw@paragw.zapto.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

NetLabel: convert to an extensibile/sparse category bitmap

The original NetLabel category bitmap was a straight char bitmap which worked
fine for the initial release as it only supported 240 bits due to limitations
in the CIPSO restricted bitmap tag (tag type 0x01). This patch converts that
straight char bitmap into an extensibile/sparse bitmap in order to lay the
foundation for other CIPSO tag types and protocols.

This patch also has a nice side effect in that all of the security attributes
passed by NetLabel into the LSM are now in a format which is in the host's
native byte/bit ordering which makes the LSM specific code much simpler; look
at the changes in security/selinux/ss/ebitmap.c as an example.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: peer secid consolidation for external network labeling

Now that labeled IPsec makes use of the peer_sid field in the
sk_security_struct we can remove a lot of the special cases between labeled
IPsec and NetLabel. In addition, create a new function,
security_skb_extlbl_sid(), which we can use in several places to get the
security context of the packet's external label which allows us to further
simplify the code in a few places.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

NetLabel: SELinux cleanups

This patch does a lot of cleanup in the SELinux NetLabel support code. A
summary of the changes include:

* Use RCU locking for the NetLabel state variable in the skk_security_struct
instead of using the inode_security_struct mutex.
* Remove unnecessary parameters in selinux_netlbl_socket_post_create().
* Rename selinux_netlbl_sk_clone_security() to
selinux_netlbl_sk_security_clone() to better fit the other NetLabel
sk_security functions.
* Improvements to selinux_netlbl_inode_permission() to help reduce the cost of
the common case.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

NetLabel: make netlbl_lsm_secattr struct easier/quicker to understand

The existing netlbl_lsm_secattr struct required the LSM to check all of the
fields to determine if any security attributes were present resulting in a lot
of work in the common case of no attributes. This patch adds a 'flags' field
which is used to indicate which attributes are present in the structure; this
should allow the LSM to do a quick comparison to determine if the structure
holds any security attributes.

Example:

if (netlbl_lsm_secattr->flags)
/* security attributes present */
else
/* NO security attributes present */

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: validate kernel object classes and permissions

This is a new object class and permission validation scheme that validates
against the defined kernel headers. This scheme allows extra classes
and permissions that do not conflict with the kernel definitions to be
added to the policy. This validation is now done for all policy loads,
not just subsequent loads after the first policy load.

The implementation walks the three structrures containing the defined
object class and permission values and ensures their values are the
same in the policy being loaded. This includes verifying the object
classes themselves, the permissions they contain, and the permissions
they inherit from commons. Classes or permissions that are present in the
kernel but missing from the policy cause a warning (printed to KERN_INFO)
to be printed, but do not stop the policy from loading, emulating current
behavior. Any other inconsistencies cause the load to fail.

Signed-off-by: Chad Sellers <csellers@tresys.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

SELinux: remove current object class and permission validation mechanism

Removes the current SELinux object class and permission validation code,
as the current code makes it impossible to change or remove object classes
and permissions on a running system. Additionally, the current code does
not actually validate that the classes and permissions are correct, but
instead merely validates that they do not change between policy reloads.

Signed-off-by: Chad Sellers <csellers@tresys.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

[NetLabel]: protect the CIPSOv4 socket option from setsockopt()

This patch makes two changes to protect applications from either removing or
tampering with the CIPSOv4 IP option on a socket. The first is the requirement
that applications have the CAP_NET_RAW capability to set an IPOPT_CIPSO option
on a socket; this prevents untrusted applications from setting their own
CIPSOv4 security attributes on the packets they send. The second change is to
SELinux and it prevents applications from setting any IPv4 options when there
is an IPOPT_CIPSO option already present on the socket; this prevents
applications from removing CIPSOv4 security attributes from the packets they
send.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

NetLabel: better error handling involving mls_export_cat()

Upon inspection it looked like the error handling for mls_export_cat() was
rather poor. This patch addresses this by NULL'ing out kfree()'d pointers
before returning and checking the return value of the function everywhere
it is called.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

NetLabel: use SECINITSID_UNLABELED for a base SID

This patch changes NetLabel to use SECINITSID_UNLABLELED as it's source of
SELinux type information when generating a NetLabel context.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

NetLabel: fix a cache race condition

Testing revealed a problem with the NetLabel cache where a cached entry could
be freed while in use by the LSM layer causing an oops and other problems.
This patch fixes that problem by introducing a reference counter to the cache
entry so that it is only freed when it is no longer in use.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

[PATCH] SELinux: change isec semaphore to a mutex

This patch converts the remaining isec->sem into a mutex. Very similar
locking is provided as before only in the faster smaller mutex rather than a
semaphore. An out_unlock path is introduced rather than the conditional
unlocking found in the original code.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>