lsm: use 32-bit compatible data types in LSM syscalls

Change the size parameters in lsm_list_modules(), lsm_set_self_attr()
and lsm_get_self_attr() from size_t to u32. This avoids the need to
have different interfaces for 32 and 64 bit systems.

Cc: stable@vger.kernel.org
Fixes: a04a1198088a ("LSM: syscalls for current process attributes")
Fixes: ad4aff9ec25f ("LSM: Create lsm_list_modules system call")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-and-reviewed-by: Dmitry V. Levin <ldv@strace.io>
[PM: subject and metadata tweaks, syscall.h fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

security: Align inode_setattr hook definition with EVM

Add the idmap parameter to the definition, so that evm_inode_setattr() can
be registered as this hook implementation.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Smack: use init_task_smack() in smack_cred_transfer()

smack_cred_transfer() open codes the same initialization
as init_task_smack(). Remove the open coding and replace it
with a call to init_task_smack().

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Initialize the in-memory inode in smack_inode_init_security()

Currently, Smack initializes in-memory new inodes in three steps. It first
sets the xattrs in smack_inode_init_security(), fetches them in
smack_d_instantiate() and finally, in the same function, sets the in-memory
inodes depending on xattr values, unless they are in specially-handled
filesystems.

Other than being inefficient, this also prevents filesystems not supporting
xattrs from working properly since, without xattrs, there is no way to pass
the label determined in smack_inode_init_security() to
smack_d_instantiate().

Since the LSM infrastructure allows setting and getting the security field
without xattrs through the inode_setsecurity and inode_getsecurity hooks,
make the inode creation work too, by initializing the in-memory inode
earlier in smack_inode_init_security().

Also mark the inode as instantiated, to prevent smack_d_instantiate() from
overwriting the security field. As mentioned above, this potentially has
impact for inodes in specially-handled filesystems in
smack_d_instantiate(), if they are not handled in the same way in
smack_inode_init_security().

Filesystems other than tmpfs don't call security_inode_init_security(), so
they would be always initialized in smack_d_instantiate(), as before. For
tmpfs, the current behavior is to assign to inodes the label '*', but
actually that label is overwritten with the one fetched from the SMACK64
xattr, set in smack_inode_init_security() (default: '_').

Initializing the in-memory inode is straightforward: if not transmuting,
nothing more needs to be done; if transmuting, overwrite the current inode
label with the one from the parent directory, and set SMK_INODE_TRANSMUTE.
Finally, set SMK_INODE_INSTANT for all cases, to mark the inode as
instantiated.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Always determine inode labels in smack_inode_init_security()

The inode_init_security hook is already a good place to initialize the
in-memory inode. And that is also what SELinux does.

In preparation for this, move the existing smack_inode_init_security() code
outside the 'if (xattr)' condition, and set the xattr, if provided.

This change does not have any impact on the current code, since every time
security_inode_init_security() is called, the initxattr() callback is
passed and, thus, xattr is non-NULL.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity()

If the SMACK64TRANSMUTE xattr is provided, and the inode is a directory,
update the in-memory inode flags by setting SMK_INODE_TRANSMUTE.

Cc: stable@vger.kernel.org
Fixes: 5c6d1125f8db ("Smack: Transmute labels on specified directories") # v2.6.38.x
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Set SMACK64TRANSMUTE only for dirs in smack_inode_setxattr()

Since the SMACK64TRANSMUTE xattr makes sense only for directories, enforce
this restriction in smack_inode_setxattr().

Cc: stable@vger.kernel.org
Fixes: 5c6d1125f8db ("Smack: Transmute labels on specified directories") # v2.6.38.x
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

io_uring: split out cmd api into a separate header

linux/io_uring.h is slowly becoming a rubbish bin where we put
anything exposed to other subsystems. For instance, the task exit
hooks and io_uring cmd infra are completely orthogonal and don't need
each other's definitions. Start cleaning it up by splitting out all
command bits into a new header file.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7ec50bae6e21f371d3850796e716917fc141225a.1701391955.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

lsm: new security_file_ioctl_compat() hook

Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).

However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.

This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".

This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.

Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.

Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2f7 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni <alpic@google.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore <paul@paul-moore.com>

shm: Slim down dependencies

list_head is in types.h, not list.h., and the uapi header wasn't needed.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

lsm: mark the lsm_id variables are marked as static

As the kernel test robot helpfully reminded us, all of the lsm_id
instances defined inside the various LSMs should be marked as static.
The one exception is Landlock which uses its lsm_id variable across
multiple source files with an extern declaration in a header file.

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

lsm: consolidate buffer size handling into lsm_fill_user_ctx()

While we have a lsm_fill_user_ctx() helper function designed to make
life easier for LSMs which return lsm_ctx structs to userspace, we
didn't include all of the buffer length safety checks and buffer
padding adjustments in the helper. This led to code duplication
across the different LSMs and the possibility for mistakes across the
different LSM subsystems. In order to reduce code duplication and
decrease the chances of silly mistakes, we're consolidating all of
this code into the lsm_fill_user_ctx() helper.

The buffer padding is also modified from a fixed 8-byte alignment to
an alignment that matches the word length of the machine
(BITS_PER_LONG / 8).

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

Smack: implement setselfattr and getselfattr hooks

Implement Smack support for security_[gs]etselfattr.
Refactor the setprocattr hook to avoid code duplication.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

LSM: Identify modules by more than name

Create a struct lsm_id to contain identifying information about Linux
Security Modules (LSMs). At inception this contains the name of the
module and an identifier associated with the security module. Change
the security_add_hooks() interface to use this structure. Change the
individual modules to maintain their own struct lsm_id and pass it to
security_add_hooks().

The values are for LSM identifiers are defined in a new UAPI
header file linux/lsm.h. Each existing LSM has been updated to
include it's LSMID in the lsm_id.

The LSM ID values are sequential, with the oldest module
LSM_ID_CAPABILITY being the lowest value and the existing modules
numbered in the order they were included in the main line kernel.
This is an arbitrary convention for assigning the values, but
none better presents itself. The value 0 is defined as being invalid.
The values 1-99 are reserved for any special case uses which may
arise in the future. This may include attributes of the LSM
infrastructure itself, possibly related to namespacing or network
attribute management. A special range is identified for such attributes
to help reduce confusion for developers unfamiliar with LSMs.

LSM attribute values are defined for the attributes presented by
modules that are available today. As with the LSM IDs, The value 0
is defined as being invalid. The values 1-99 are reserved for any
special case uses which may arise in the future.

Cc: linux-security-module <linux-security-module@vger.kernel.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Mickael Salaun <mic@digikod.net>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Nacked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
[PM: forward ported beyond v6.6 due merge window changes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

smack: Set the SMACK64TRANSMUTE xattr in smack_inode_init_security()

With the newly added ability of LSMs to supply multiple xattrs, set
SMACK64TRASMUTE in smack_inode_init_security(), instead of d_instantiate().
Do it by incrementing SMACK_INODE_INIT_XATTRS to 2 and by calling
lsm_get_xattr_slot() a second time, if the transmuting conditions are met.

The LSM infrastructure passes all xattrs provided by LSMs to the
filesystems through the initxattrs() callback, so that filesystems can
store xattrs in the disk.

After the change, the SMK_INODE_TRANSMUTE inode flag is always set by
d_instantiate() after fetching SMACK64TRANSMUTE from the disk. Before it
was done by smack_inode_post_setxattr() as result of the __vfs_setxattr()
call.

Removing __vfs_setxattr() also prevents invalidating the EVM HMAC, by
adding a new xattr without checking and updating the existing HMAC.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security: Allow all LSMs to provide xattrs for inode_init_security hook

Currently, the LSM infrastructure supports only one LSM providing an xattr
and EVM calculating the HMAC on that xattr, plus other inode metadata.

Allow all LSMs to provide one or multiple xattrs, by extending the security
blob reservation mechanism. Introduce the new lbs_xattr_count field of the
lsm_blob_sizes structure, so that each LSM can specify how many xattrs it
needs, and the LSM infrastructure knows how many xattr slots it should
allocate.

Modify the inode_init_security hook definition, by passing the full
xattr array allocated in security_inode_init_security(), and the current
number of xattr slots in that array filled by LSMs. The first parameter
would allow EVM to access and calculate the HMAC on xattrs supplied by
other LSMs, the second to not leave gaps in the xattr array, when an LSM
requested but did not provide xattrs (e.g. if it is not initialized).

Introduce lsm_get_xattr_slot(), which LSMs can call as many times as the
number specified in the lbs_xattr_count field of the lsm_blob_sizes
structure. During each call, lsm_get_xattr_slot() increments the number of
filled xattrs, so that at the next invocation it returns the next xattr
slot to fill.

Cleanup security_inode_init_security(). Unify the !initxattrs and
initxattrs case by simply not allocating the new_xattrs array in the
former. Update the documentation to reflect the changes, and fix the
description of the xattr name, as it is not allocated anymore.

Adapt both SELinux and Smack to use the new definition of the
inode_init_security hook, and to call lsm_get_xattr_slot() to obtain and
fill the reserved slots in the xattr array.

Move the xattr->name assignment after the xattr->value one, so that it is
done only in case of successful memory allocation.

Finally, change the default return value of the inode_init_security hook
from zero to -EOPNOTSUPP, so that BPF LSM correctly follows the hook
conventions.

Reported-by: Nicolas Bouchinet <nicolas.bouchinet@clip-os.org>
Link: https://lore.kernel.org/linux-integrity/Y1FTSIo+1x+4X0LS@archlinux/
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: minor comment and variable tweaks, approved by RS]
Signed-off-by: Paul Moore <paul@paul-moore.com>

vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing

When NFS superblocks are created by automounting, their LSM parameters
aren't set in the fs_context struct prior to sget_fc() being called,
leading to failure to match existing superblocks.

This bug leads to messages like the following appearing in dmesg when
fscache is enabled:

NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)

Fix this by adding a new LSM hook to load fc->security for submount
creation.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
Fixes: 9bc61ab18b1d ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
Fixes: 779df6a5480f ("NFS: Ensure security label is set for root inode")
Tested-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230808-master-v9-1-e0ecde888221@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

smack: Record transmuting in smk_transmuted

smack_dentry_create_files_as() determines whether transmuting should occur
based on the label of the parent directory the new inode will be added to,
and not the label of the directory where it is created.

This helps for example to do transmuting on overlayfs, since the latter
first creates the inode in the working directory, and then moves it to the
correct destination.

However, despite smack_dentry_create_files_as() provides the correct label,
smack_inode_init_security() does not know from passed information whether
or not transmuting occurred. Without this information,
smack_inode_init_security() cannot set SMK_INODE_CHANGED in smk_flags,
which will result in the SMACK64TRANSMUTE xattr not being set in
smack_d_instantiate().

Thus, add the smk_transmuted field to the task_smack structure, and set it
in smack_dentry_create_files_as() to smk_task if transmuting occurred. If
smk_task is equal to smk_transmuted in smack_inode_init_security(), act as
if transmuting was successful but without taking the label from the parent
directory (the inode label was already set correctly from the current
credentials in smack_inode_alloc_security()).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Retrieve transmuting information in smack_inode_getsecurity()

Enhance smack_inode_getsecurity() to retrieve the value for
SMACK64TRANSMUTE from the inode security blob, similarly to SMACK64.

This helps to display accurate values in the situation where the security
labels come from mount options and not from xattrs.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Improve mount process memory use

The existing mount processing code in Smack makes many unnecessary
copies of Smack labels. Because Smack labels never go away once
imported it is safe to use pointers to them rather than copies.
Replace the use of copies of label names to pointers to the global
label list entries.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

selinux: remove the runtime disable functionality

After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality. The existing kernel deprecation
notice explains the functionality and why we want to remove it:

The selinuxfs "disable" node allows SELinux to be disabled at
runtime prior to a policy being loaded into the kernel. If
disabled via this mechanism, SELinux will remain disabled until
the system is rebooted.

The preferred method of disabling SELinux is via the "selinux=0"
boot parameter, but the selinuxfs "disable" node was created to
make it easier for systems with primitive bootloaders that did not
allow for easy modification of the kernel command line.
Unfortunately, allowing for SELinux to be disabled at runtime makes
it difficult to secure the kernel's LSM hooks using the
"__ro_after_init" feature.

It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.

From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.

It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.

Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage. In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

smack_lsm: remove unnecessary type casting

Remove unnecessary type casting.
The type of inode variable is struct inode *, so no type casting required.

Signed-off-by: XU pengfei <xupengfei@nfschina.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

fs: port acl to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

fs: port xattr to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

fs: port ->permission() to pass mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

lsm: make security_socket_getpeersec_stream() sockptr_t safe

Commit 4ff09db1b79b ("bpf: net: Change sk_getsockopt() to take the
sockptr_t argument") made it possible to call sk_getsockopt()
with both user and kernel address space buffers through the use of
the sockptr_t type. Unfortunately at the time of conversion the
security_socket_getpeersec_stream() LSM hook was written to only
accept userspace buffers, and in a desire to avoid having to change
the LSM hook the commit author simply passed the sockptr_t's
userspace buffer pointer. Since the only sk_getsockopt() callers
at the time of conversion which used kernel sockptr_t buffers did
not allow SO_PEERSEC, and hence the
security_socket_getpeersec_stream() hook, this was acceptable but
also very fragile as future changes presented the possibility of
silently passing kernel space pointers to the LSM hook.

There are several ways to protect against this, including careful
code review of future commits, but since relying on code review to
catch bugs is a recipe for disaster and the upstream eBPF maintainer
is "strongly against defensive programming", this patch updates the
LSM hook, and all of the implementations to support sockptr_t and
safely handle both user and kernel space buffers.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

smack: implement get, set and remove acl hook

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

So far posix acls were passed as a void blob to the security and
integrity modules. Some of them like evm then proceed to interpret the
void pointer and convert it into the kernel internal struct posix acl
representation to perform their integrity checking magic. This is
obviously pretty problematic as that requires knowledge that only the
vfs is guaranteed to have and has lead to various bugs. Add a proper
security hook for setting posix acls and pass down the posix acls in
their appropriate vfs format instead of hacking it through a void
pointer stored in the uapi format.

I spent considerate time in the security module infrastructure and
audited all codepaths. Smack has no restrictions based on the posix
acl values passed through it. The capability hook doesn't need to be
called either because it only has restrictions on security.* xattrs. So
these all becomes very simple hooks for smack.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

->getprocattr(): attribute name is const char *, TYVM...

cast of ->d_name.name to char * is completely wrong - nothing is
allowed to modify its contents.

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

smack: lsm: remove the unneeded result variable

Return the value smk_ptrace_rule_check() directly instead of storing it
in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Add sk_clone_security LSM hook

Using smk_of_current() during sk_alloc_security hook leads in
rare cases to a faulty initialization of the security context
of the created socket.

By adding the LSM hook sk_clone_security to SMACK this initialization
fault is corrected by copying the security context of the old socket
pointer to the newly cloned one.

Co-authored-by: Martin Ostertag: <martin.ostertag@elektrobit.com>
Signed-off-by: Lontke Michael <michael.lontke@elektrobit.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Provide read control for io_uring_cmd

Limit io_uring "cmd" options to files for which the caller has
Smack read access. There may be cases where the cmd option may
be closer to a write access than a read, but there is no way
to make that determination.

Cc: stable@vger.kernel.org
Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

smack: Remove the redundant lsm_inode_alloc

It's not possible for inode->i_security to be NULL here because every
inode will call inode_init_always and then lsm_inode_alloc to alloc
memory for inode->security, this is what LSM infrastructure management
do, so remove this redundant code.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Fix incorrect type in assignment of ipv6 port for audit

Remove inappropriate use of ntohs() and assign the
port value directly.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

lsm: security_task_getsecid_subj() -> security_current_getsecid_subj()

The security_task_getsecid_subj() LSM hook invites misuse by allowing
callers to specify a task even though the hook is only safe when the
current task is referenced. Fix this by removing the task_struct
argument to the hook, requiring LSM implementations to use the
current task. While we are changing the hook declaration we also
rename the function to security_current_getsecid_subj() in an effort
to reinforce that the hook captures the subjective credentials of the
current task and not an arbitrary task on the system.

Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Smack: fix W=1 build warnings

A couple of functions had malformed comment blocks.
Namespace parameters were added without updating the
comment blocks. These are all repaired in the Smack code,
so "% make W=1 security/smack" is warning free.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack:- Use overlay inode label in smack_inode_copy_up()

Currently in "smack_inode_copy_up()" function, process label is
changed with the label on parent inode. Due to which,
process is assigned directory label and whatever file or directory
created by the process are also getting directory label
which is wrong label.

Changes has been done to use label of overlay inode instead
of parent inode.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Guard smack_ipv6_lock definition within a SMACK_IPV6_PORT_LABELING block

The mutex smack_ipv6_lock is only used with the SMACK_IPV6_PORT_LABELING
block but its definition is outside of the block. This leads to a
defined-but-not-used warning on PREEMPT_RT.

Moving smack_ipv6_lock down to the block where it is used where it used
raises the question why is smk_ipv6_port_list read if nothing is added
to it.
Turns out, only smk_ipv6_port_check() is using it outside of an ifdef
SMACK_IPV6_PORT_LABELING block. However two of three caller invoke
smk_ipv6_port_check() from a ifdef block and only one is using
__is_defined() macro which requires the function and smk_ipv6_port_list
to be around.

Put the lock and list inside an ifdef SMACK_IPV6_PORT_LABELING block to
avoid the warning regarding unused mutex. Extend the ifdef-block to also
cover smk_ipv6_port_check(). Make smack_socket_connect() use ifdef
instead of __is_defined() to avoid complains about missing function.

Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Brutalist io_uring support

Add Smack privilege checks for io_uring. Use CAP_MAC_OVERRIDE
for the override_creds case and CAP_MAC_ADMIN for creating a
polling thread. These choices are based on conjecture regarding
the intent of the surrounding code.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: make the smack_uring_* funcs static, remove debug code]
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux,smack: fix subjective/objective credential use mixups

Jann Horn reported a problem with commit eb1231f73c4d ("selinux:
clarify task subjective and objective credentials") where some LSM
hooks were attempting to access the subjective credentials of a task
other than the current task. Generally speaking, it is not safe to
access another task's subjective credentials and doing so can cause
a number of problems.

Further, while looking into the problem, I realized that Smack was
suffering from a similar problem brought about by a similar commit
1fb057dcde11 ("smack: differentiate between subjective and objective
task credentials").

This patch addresses this problem by restoring the use of the task's
objective credentials in those cases where the task is other than the
current executing task. Not only does this resolve the problem
reported by Jann, it is arguably the correct thing to do in these
cases.

Cc: stable@vger.kernel.org
Fixes: eb1231f73c4d ("selinux: clarify task subjective and objective credentials")
Fixes: 1fb057dcde11 ("smack: differentiate between subjective and objective task credentials")
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

smack: mark 'smack_enabled' global variable as __initdata

Mark 'smack_enabled' as __initdata
since it is only used during initialization code.

Signed-off-by: Austin Kim <austin.kim@lge.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.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>

smack: differentiate between subjective and objective task credentials

With the split of the security_task_getsecid() into subjective and
objective variants it's time to update Smack to ensure it is using
the correct task creds.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

lsm: separate security_task_getsecid() into subjective and objective variants

Of the three LSMs that implement the security_task_getsecid() LSM
hook, all three LSMs provide the task's objective security
credentials. This turns out to be unfortunate as most of the hook's
callers seem to expect the task's subjective credentials, although
a small handful of callers do correctly expect the objective
credentials.

This patch is the first step towards fixing the problem: it splits
the existing security_task_getsecid() hook into two variants, one
for the subjective creds, one for the objective creds.

void security_task_getsecid_subj(struct task_struct *p,
u32 *secid);
void security_task_getsecid_obj(struct task_struct *p,
u32 *secid);

While this patch does fix all of the callers to use the correct
variant, in order to keep this patch focused on the callers and to
ease review, the LSMs continue to use the same implementation for
both hooks. The net effect is that this patch should not change
the behavior of the kernel in any way, it will be up to the latter
LSM specific patches in this series to change the hook
implementations and return the correct credentials.

Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA)
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

commoncap: handle idmapped mounts

When interacting with user namespace and non-user namespace aware
filesystem capabilities the vfs will perform various security checks to
determine whether or not the filesystem capabilities can be used by the
caller, whether they need to be removed and so on. The main
infrastructure for this resides in the capability codepaths but they are
called through the LSM security infrastructure even though they are not
technically an LSM or optional. This extends the existing security hooks
security_inode_removexattr(), security_inode_killpriv(),
security_inode_getsecurity() to pass down the mount's user namespace and
makes them aware of idmapped mounts.

In order to actually get filesystem capabilities from disk the
capability infrastructure exposes the get_vfs_caps_from_disk() helper.
For user namespace aware filesystem capabilities a root uid is stored
alongside the capabilities.

In order to determine whether the caller can make use of the filesystem
capability or whether it needs to be ignored it is translated according
to the superblock's user namespace. If it can be translated to uid 0
according to that id mapping the caller can use the filesystem
capabilities stored on disk. If we are accessing the inode that holds
the filesystem capabilities through an idmapped mount we map the root
uid according to the mount's user namespace. Afterwards the checks are
identical to non-idmapped mounts: reading filesystem caps from disk
enforces that the root uid associated with the filesystem capability
must have a mapping in the superblock's user namespace and that the
caller is either in the same user namespace or is a descendant of the
superblock's user namespace. For filesystems that are mountable inside
user namespace the caller can just mount the filesystem and won't
usually need to idmap it. If they do want to idmap it they can create an
idmapped mount and mark it with a user namespace they created and which
is thus a descendant of s_user_ns. For filesystems that are not
mountable inside user namespaces the descendant rule is trivially true
because the s_user_ns will be the initial user namespace.

If the initial user namespace is passed nothing changes so non-idmapped
mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-11-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

xattr: handle idmapped mounts

When interacting with extended attributes the vfs verifies that the
caller is privileged over the inode with which the extended attribute is
associated. For posix access and posix default extended attributes a uid
or gid can be stored on-disk. Let the functions handle posix extended
attributes on idmapped mounts. If the inode is accessed through an
idmapped mount we need to map it according to the mount's user
namespace. Afterwards the checks are identical to non-idmapped mounts.
This has no effect for e.g. security xattrs since they don't store uids
or gids and don't perform permission checks on them like posix acls do.

Link: https://lore.kernel.org/r/20210121131959.646623-10-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

security: add const qualifier to struct sock in various places

A followup change to tcp_request_sock_op would have to drop the 'const'
qualifier from the 'route_req' function as the
'security_inet_conn_request' call is moved there - and that function
expects a 'struct sock *'.

However, it turns out its also possible to add a const qualifier to
security_inet_conn_request instead.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

security/smack: remove unused varible 'rc'

This varible isn't used and can be removed to avoid a gcc warning:
security/smack/smack_lsm.c:3873:6: warning: variable ‘rc’ set but not
used [-Wunused-but-set-variable]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Remove unnecessary variable initialization

The initialization of rc in smack_from_netlbl() is pointless.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Fix build when NETWORK_SECMARK is not set

Use proper conditional compilation for the secmark field in
the network skb.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Use the netlabel cache

Utilize the Netlabel cache mechanism for incoming packet matching.
Refactor the initialization of secattr structures, as it was being
done in two places.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Set socket labels only once

Refactor the IP send checks so that the netlabel value
is set only when necessary, not on every send. Some functions
get renamed as the changes made the old name misleading.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Consolidate uses of secmark into a function

Add a function smack_from_skb() that returns the Smack label
identified by a network secmark. Replace the explicit uses of
the secmark with this function.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds

Today security_bprm_set_creds has several implementations:
apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds,
smack_bprm_set_creds, and tomoyo_bprm_set_creds.

Except for cap_bprm_set_creds they all test bprm->called_set_creds and
return immediately if it is true. The function cap_bprm_set_creds
ignores bprm->calld_sed_creds entirely.

Create a new LSM hook security_bprm_creds_for_exec that is called just
before prepare_binprm in __do_execve_file, resulting in a LSM hook
that is called exactly once for the entire of exec. Modify the bits
of security_bprm_set_creds that only want to be called once per exec
into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds
behind.

Remove bprm->called_set_creds all of it's former users have been moved
to security_bprm_creds_for_exec.

Add or upate comments a appropriate to bring them up to date and
to reflect this change.

Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com> # For the LSM and Smack bits
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

smack: Implement the watch_key and post_notification hooks

Implement the watch_key security hook in Smack to make sure that a key
grants the caller Read permission in order to set a watch on a key.

Also implement the post_notification security hook to make sure that the
notification source is granted Write permission by the watch queue.

For the moment, the watch_devices security hook is left unimplemented as
it's not obvious what the object should be since the queue is global and
didn't previously exist.

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

keys: Make the KEY_NEED_* perms an enum rather than a mask

Since the meaning of combining the KEY_NEED_* constants is undefined, make
it so that you can't do that by turning them into an enum.

The enum is also given some extra values to represent special
circumstances, such as:

(1) The '0' value is reserved and causes a warning to trap the parameter
being unset.

(2) The key is to be unlinked and we require no permissions on it, only
the keyring, (this replaces the KEY_LOOKUP_FOR_UNLINK flag).

(3) An override due to CAP_SYS_ADMIN.

(4) An override due to an instantiation token being present.

(5) The permissions check is being deferred to later key_permission()
calls.

The extra values give the opportunity for LSMs to audit these situations.

[Note: This really needs overhauling so that lookup_user_key() tells
key_task_permission() and the LSM what operation is being done and leaves
it to those functions to decide how to map that onto the available
permits. However, I don't really want to make these change in the middle
of the notifications patchset.]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
cc: Paul Moore <paul@paul-moore.com>
cc: Stephen Smalley <stephen.smalley.work@gmail.com>
cc: Casey Schaufler <casey@schaufler-ca.com>
cc: keyrings@vger.kernel.org
cc: selinux@vger.kernel.org

Smack:- Remove redundant inode_smack cache

The inode_smack cache is no longer used.
Remove it.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack:- Remove mutex lock "smk_lock" from inode_smack

"smk_lock" mutex is used during inode instantiation in
smack_d_instantiate()function. It has been used to avoid
simultaneous access on same inode security structure.
Since smack related initialization is done only once i.e during
inode creation. If the inode has already been instantiated then
smack_d_instantiate() function just returns without doing
anything.

So it means mutex lock is required only during inode creation.
But since 2 processes can't create same inodes or files
simultaneously. Also linking or some other file operation can't
be done simultaneously when the file is getting created since
file lookup will fail before dentry inode linkup which is done
after smack initialization.
So no mutex lock is required in inode_smack structure.

It will save memory as well as improve some performance.
If 40000 inodes are created in system, it will save 1.5 MB on
32-bit systems & 2.8 MB on 64-bit systems.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: avoid unused 'sip' variable warning

The mix of IS_ENABLED() and #ifdef checks has left a combination
that causes a warning about an unused variable:

security/smack/smack_lsm.c: In function 'smack_socket_connect':
security/smack/smack_lsm.c:2838:24: error: unused variable 'sip' [-Werror=unused-variable]
2838 | struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;

Change the code to use C-style checks consistently so the compiler
can handle it correctly.

Fixes: 87fbfffcc89b ("broken ping to ipv6 linklocal addresses on debian buster")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

fs_parse: fold fs_parameter_desc/fs_parameter_spec

The former contains nothing but a pointer to an array of the latter...

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

fs_parser: remove fs_parameter_description name field

Unused now.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

broken ping to ipv6 linklocal addresses on debian buster

I am seeing ping failures to IPv6 linklocal addresses with Debian
buster. Easiest example to reproduce is:

$ ping -c1 -w1 ff02::1%eth1
connect: Invalid argument

$ ping -c1 -w1 ff02::1%eth1
PING ff02::01%eth1(ff02::1%eth1) 56 data bytes
64 bytes from fe80::e0:f9ff:fe0c:37%eth1: icmp_seq=1 ttl=64 time=0.059 ms

git bisect traced the failure to
commit b9ef5513c99b ("smack: Check address length before reading address family")

Arguably ping is being stupid since the buster version is not setting
the address family properly (ping on stretch for example does):

$ strace -e connect ping6 -c1 -w1 ff02::1%eth1
connect(5, {sa_family=AF_UNSPEC,
sa_data="\4\1\0\0\0\0\377\2\0\0\0\0\0\0\0\0\0\0\0\0\0\1\3\0\0\0"}, 28)
= -1 EINVAL (Invalid argument)

but the command works fine on kernels prior to this commit, so this is
breakage which goes against the Linux paradigm of "don't break userspace"

Cc: stable@vger.kernel.org
Reported-by: David Ahern <dsahern@gmail.com>
Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

 security/smack/smack_lsm.c | 41 +++++++++++++++++++----------------------
1 file changed, 19 insertions(+), 22 deletions(-)

pipe: Reduce #inclusion of pipe_fs_i.h

Remove some #inclusions of linux/pipe_fs_i.h that don't seem to be
necessary any more.

Signed-off-by: David Howells <dhowells@redhat.com>

smack: use GFP_NOFS while holding inode_smack::smk_lock

inode_smack::smk_lock is taken during smack_d_instantiate(), which is
called during a filesystem transaction when creating a file on ext4.
Therefore to avoid a deadlock, all code that takes this lock must use
GFP_NOFS, to prevent memory reclaim from waiting for the filesystem
transaction to complete.

Reported-by: syzbot+0eefc1e06a77d327a056@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security: smack: Fix possible null-pointer dereferences in smack_socket_sock_rcv_skb()

In smack_socket_sock_rcv_skb(), there is an if statement
on line 3920 to check whether skb is NULL:
if (skb && skb->secmark != 0)

This check indicates skb can be NULL in some cases.

But on lines 3931 and 3932, skb is used:
ad.a.u.net->netif = skb->skb_iif;
ipv6_skb_to_auditdata(skb, &ad.a, NULL);

Thus, possible null-pointer dereferences may occur when skb is NULL.

To fix these possible bugs, an if statement is added to check skb.

These bugs are found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: fix some kernel-doc notations

Fix/add kernel-doc notation and fix typos in security/smack/.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Don't ignore other bprm->unsafe flags if LSM_UNSAFE_PTRACE is set

There is a logic bug in the current smack_bprm_set_creds():
If LSM_UNSAFE_PTRACE is set, but the ptrace state is deemed to be
acceptable (e.g. because the ptracer detached in the meantime), the other
->unsafe flags aren't checked. As far as I can tell, this means that
something like the following could work (but I haven't tested it):

- task A: create task B with fork()
- task B: set NO_NEW_PRIVS
- task B: install a seccomp filter that makes open() return 0 under some
conditions
- task B: replace fd 0 with a malicious library
- task A: attach to task B with PTRACE_ATTACH
- task B: execve() a file with an SMACK64EXEC extended attribute
- task A: while task B is still in the middle of execve(), exit (which
destroys the ptrace relationship)

Make sure that if any flags other than LSM_UNSAFE_PTRACE are set in
bprm->unsafe, we reject the execve().

Cc: stable@vger.kernel.org
Fixes: 5663884caab1 ("Smack: unify all ptrace accesses in the smack")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"

This reverts merge 0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (and thus
effectively commits

7a1ade847596 ("keys: Provide KEYCTL_GRANT_PERMISSION")
2e12256b9a76 ("keys: Replace uid/gid/perm permissions checking with an ACL")

that the merge brought in).

It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].

The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.

[1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
[2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/

Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

keys: Replace uid/gid/perm permissions checking with an ACL

Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split. This will also allow a
greater range of subjects to represented.

============
WHY DO THIS?
============

The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.

For SETATTR, this includes actions that are about controlling access to a
key:

(1) Changing a key's ownership.

(2) Changing a key's security information.

(3) Setting a keyring's restriction.

And actions that are about managing a key's lifetime:

(4) Setting an expiry time.

(5) Revoking a key.

and (proposed) managing a key as part of a cache:

(6) Invalidating a key.

Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.

Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission. It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.

As for SEARCH permission, that currently covers:

(1) Finding keys in a keyring tree during a search.

(2) Permitting keyrings to be joined.

(3) Invalidation.

But these don't really belong together either, since these actions really
need to be controlled separately.

Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.


===============
WHAT IS CHANGED
===============

The SETATTR permission is split to create two new permissions:

(1) SET_SECURITY - which allows the key's owner, group and ACL to be
changed and a restriction to be placed on a keyring.

(2) REVOKE - which allows a key to be revoked.

The SEARCH permission is split to create:

(1) SEARCH - which allows a keyring to be search and a key to be found.

(2) JOIN - which allows a keyring to be joined as a session keyring.

(3) INVAL - which allows a key to be invalidated.

The WRITE permission is also split to create:

(1) WRITE - which allows a key's content to be altered and links to be
added, removed and replaced in a keyring.

(2) CLEAR - which allows a keyring to be cleared completely. This is
split out to make it possible to give just this to an administrator.

(3) REVOKE - see above.


Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together. An ACE specifies a subject, such as:

(*) Possessor - permitted to anyone who 'possesses' a key
(*) Owner - permitted to the key owner
(*) Group - permitted to the key group
(*) Everyone - permitted to everyone

Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.

Further subjects may be made available by later patches.

The ACE also specifies a permissions mask. The set of permissions is now:

VIEW Can view the key metadata
READ Can read the key content
WRITE Can update/modify the key content
SEARCH Can find the key by searching/requesting
LINK Can make a link to the key
SET_SECURITY Can change owner, ACL, expiry
INVAL Can invalidate
REVOKE Can revoke
JOIN Can join this keyring
CLEAR Can clear this keyring


The KEYCTL_SETPERM function is then deprecated.

The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.

The KEYCTL_INVALIDATE function then requires INVAL.

The KEYCTL_REVOKE function then requires REVOKE.

The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.

The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.


======================
BACKWARD COMPATIBILITY
======================

To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.

It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.

SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned
on if a keyring is being altered.

The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.

It will make the following mappings:

(1) INVAL, JOIN -> SEARCH

(2) SET_SECURITY -> SETATTR

(3) REVOKE -> WRITE if SETATTR isn't already set

(4) CLEAR -> WRITE

Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.


=======
TESTING
=======

This passes the keyutils testsuite for all but a couple of tests:

(1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
if the type doesn't have ->read(). You still can't actually read the
key.

(2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
work as Other has been replaced with Everyone in the ACL.

Signed-off-by: David Howells <dhowells@redhat.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 version 2 as
published by the free software foundation

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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Smack: Restore the smackfsdef mount option and add missing prefixes

The 5.1 mount system rework changed the smackfsdef mount option to
smackfsdefault. This fixes the regression by making smackfsdef treated
the same way as smackfsdefault.

Also fix the smack_param_specs[] to have "smack" prefixes on all the
names. This isn't visible to a user unless they either:

(a) Try to mount a filesystem that's converted to the internal mount API
and that implements the ->parse_monolithic() context operation - and
only then if they call security_fs_context_parse_param() rather than
security_sb_eat_lsm_opts().

There are no examples of this upstream yet, but nfs will probably want
to do this for nfs2 or nfs3.

(b) Use fsconfig() to configure the filesystem - in which case
security_fs_context_parse_param() will be called.

This issue is that smack_sb_eat_lsm_opts() checks for the "smack" prefix
on the options, but smack_fs_context_parse_param() does not.

Fixes: c3300aaf95fb ("smack: get rid of match_token()")
Fixes: 2febd254adc4 ("smack: Implement filesystem context security hooks")
Cc: stable@vger.kernel.org
Reported-by: Jose Bollo <jose.bollo@iot.bzh>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Smack: Fix kbuild reported build error

The variable sap is defined under ifdef, but a recently
added use of the variable was not. Put that use under ifdef
as well.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Check address length before reading address family

KMSAN will complain if valid address length passed to bind()/connect()/
sendmsg() is shorter than sizeof("struct sockaddr"->sa_family) bytes.

Also, since smk_ipv6_port_label()/smack_netlabel_send()/
smack_ipv6host_label()/smk_ipv6_check()/smk_ipv6_port_check() are not
checking valid address length and/or address family, make sure we check
both. The minimal valid length in smack_socket_connect() is changed from
sizeof(struct sockaddr_in6) bytes to SIN6_LEN_RFC2133 bytes, for it seems
that Smack is not using "struct sockaddr_in6"->sin6_scope_id field.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Fix IPv6 handling of 0 secmark

Handle the case where the skb for an IPv6 packet contains
a 0 in the secmark for a packet generated locally. This
can only happen for system packets, so allow the access.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Create smack_rule cache to optimize memory usage

This patch allows for small memory optimization by creating the
kmem cache for "struct smack_rule" instead of using kzalloc.
For adding new smack rule, kzalloc is used to allocate the memory
for "struct smack_rule". kzalloc will always allocate 32 or 64 bytes
for 1 structure depending upon the kzalloc cache sizes available in
system. Although the size of structure is 20 bytes only, resulting
in memory wastage per object in the default pool.

For e.g., if there are 20000 rules, then it will save 240KB(20000*12)
which is crucial for small memory targets.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

introduce cloning of fs_context

new primitive: vfs_dup_fs_context(). Comes with fs_context
method (->dup()) for copying the filesystem-specific parts
of fs_context, along with LSM one (->fs_context_dup()) for
doing the same to LSM parts.

[needs better commit message, and change of Author:, anyway]

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

smack: Implement filesystem context security hooks

Implement filesystem context security hooks for the smack LSM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Casey Schaufler <casey@schaufler-ca.com>
cc: linux-security-module@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

security: mark expected switch fall-throughs and add a missing break

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

security/integrity/ima/ima_template_lib.c:85:10: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:940:18: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:943:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:972:21: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/integrity/ima/ima_policy.c:974:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/smack/smack_lsm.c:3391:9: warning: this statement may fall through [-Wimplicit-fallthrough=]
security/apparmor/domain.c:569:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Warning level 3 was used: -Wimplicit-fallthrough=3

Also, add a missing break statement to fix the following warning:

security/integrity/ima/ima_appraise.c:116:26: warning: this statement may fall through [-Wimplicit-fallthrough=]

Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

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>

LSM: Make lsm_early_cred() and lsm_early_task() local functions.

Since current->cred == current->real_cred when ordered_lsm_init()
is called, and lsm_early_cred()/lsm_early_task() need to be called
between the amount of required bytes is determined and module specific
initialization function is called, we can move these calls from
individual modules to ordered_lsm_init().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

LSM: Infrastructure management of the ipc security blob

Move management of the kern_ipc_perm->security and
msg_msg->security blobs 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.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>

Smack: Abstract use of ipc security blobs

Don't use the ipc->security pointer directly.
Don't use the msg_msg->security pointer directly.
Provide helper functions that provides the security blob pointers.

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

LSM: Infrastructure management of the inode security

Move management of the inode->i_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.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>

Smack: Abstract use of inode security blob

Don't use the inode->i_security pointer directly.
Provide a helper function that provides the security blob pointer.

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

LSM: Infrastructure management of the file security

Move management of the file->f_security blob out of the
individual security modules and into the infrastructure.
The modules no longer allocate or free the data, instead
they tell the infrastructure how much space they require.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>

Smack: Abstract use of file security blob

Don't use the file->f_security pointer directly.
Provide a helper function that provides the security blob pointer.

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

Infrastructure management of the cred security blob

Move management of the cred security blob out of the
security modules and into the security infrastructre.
Instead of allocating and freeing space the security
modules tell the infrastructure how much space they
require.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>

Smack: Abstract use of cred security blob

Don't use the cred->security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>

LSM: Separate idea of "major" LSM from "exclusive" LSM

In order to both support old "security=" Legacy Major LSM selection, and
handling real exclusivity, this creates LSM_FLAG_EXCLUSIVE and updates
the selection logic to handle them.

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

LSM: Lift LSM selection out of individual LSMs

As a prerequisite to adjusting LSM selection logic in the future, this
moves the selection logic up out of the individual major LSMs, making
their init functions only run when actually enabled. This considers all
LSMs enabled by default unless they specified an external "enable"
variable.

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

LSM: Introduce LSM_FLAG_LEGACY_MAJOR

This adds a flag for the current "major" LSMs to distinguish them when
we have a universal method for ordering all LSMs. It's called "legacy"
since the distinction of "major" will go away in the blob-sharing world.

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

smack: rewrite smack_sb_eat_lsm_opts()

make it use smack_add_opt() and avoid separate copies - gather
non-LSM options by memmove() in place

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

smack: get rid of match_token()

same issue as with selinux...

[fix by Andrei Vagin folded in]

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

smack: take the guts of smack_parse_opts_str() into a new helper

smack_add_opt() adds an already matched option to growing smack_mnt_options

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

LSM: new method: ->sb_add_mnt_opt()

Adding options to growing mnt_opts. NFS kludge with passing
context= down into non-text-options mount switched to it, and
with that the last use of ->sb_parse_opts_str() is gone.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

smack: switch to private smack_mnt_opts

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

LSM: hide struct security_mnt_opts from any generic code

Keep void * instead, allocate on demand (in parse_str_opts, at the
moment). Eventually both selinux and smack will be better off
with private structures with several strings in those, rather than
this "counter and two pointers to dynamically allocated arrays"
ugliness. This commit allows to do that at leisure, without
disrupting anything outside of given module.

Changes:
* instead of struct security_mnt_opt use an opaque pointer
initialized to NULL.
* security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and
security_free_mnt_opts() take it as var argument (i.e. as void **);
call sites are unchanged.
* security_sb_set_mnt_opts() and security_sb_remount() take
it by value (i.e. as void *).
* new method: ->sb_free_mnt_opts(). Takes void *, does
whatever freeing that needs to be done.
* ->sb_set_mnt_opts() and ->sb_remount() might get NULL as
mnt_opts argument, meaning "empty".

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

LSM: turn sb_eat_lsm_opts() into a method

Kill ->sb_copy_data() - it's used only in combination with immediately
following ->sb_parse_opts_str(). Turn that combination into a new
method.

This is just a mechanical move - cleanups will be the next step.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()

... leaving the "is it kernel-internal" logics in the caller.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

LSM: lift parsing LSM options into the caller of ->sb_kern_mount()

This paves the way for retaining the LSM options from a common filesystem
mount context during a mount parameter parsing phase to be instituted prior
to actual mount/reconfiguration actions.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

smack: make smack_parse_opts_str() clean up on failure

fixes e.g. a btrfs leak...

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

smack: fix access permissions for keyring

Function smack_key_permission() only issues smack requests for the
following operations:
- KEY_NEED_READ (issues MAY_READ)
- KEY_NEED_WRITE (issues MAY_WRITE)
- KEY_NEED_LINK (issues MAY_WRITE)
- KEY_NEED_SETATTR (issues MAY_WRITE)
A blank smack request is issued in all other cases, resulting in
smack access being granted if there is any rule defined between
subject and object, or denied with -EACCES otherwise.

Request MAY_READ access for KEY_NEED_SEARCH and KEY_NEED_VIEW.
Fix the logic in the unlikely case when both MAY_READ and
MAY_WRITE are needed. Validate access permission field for valid
contents.

Signed-off-by: Zoran Markovic <zmarkovic@sierrawireless.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>

LSM: Record LSM name in struct lsm_info

In preparation for making LSM selections outside of the LSMs, include
the name of LSMs in struct lsm_info.

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

LSM: Convert security_initcall() into DEFINE_LSM()

Instead of using argument-based initializers, switch to defining the
contents of struct lsm_info on a per-LSM basis. This also drops
the final use of the now inaccurate "initcall" naming.

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

signal: Distinguish between kernel_siginfo and siginfo

Linus recently observed that if we did not worry about the padding
member in struct siginfo it is only about 48 bytes, and 48 bytes is
much nicer than 128 bytes for allocating on the stack and copying
around in the kernel.

The obvious thing of only adding the padding when userspace is
including siginfo.h won't work as there are sigframe definitions in
the kernel that embed struct siginfo.

So split siginfo in two; kernel_siginfo and siginfo. Keeping the
traditional name for the userspace definition. While the version that
is used internally to the kernel and ultimately will not be padded to
128 bytes is called kernel_siginfo.

The definition of struct kernel_siginfo I have put in include/signal_types.h

A set of buildtime checks has been added to verify the two structures have
the same field offsets.

To make it easy to verify the change kernel_siginfo retains the same
size as siginfo. The reduction in size comes in a following change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Smack: Mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in this particular case, I replaced "No break" with a
proper "Fall through" annotation, which is what GCC is expecting
to find.

Warning level 2 was used: -Wimplicit-fallthrough=2

Addresses-Coverity-ID: 115051 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: ptrace capability use fixes

This fixes a pair of problems in the Smack ptrace checks
related to checking capabilities. In both cases, as reported
by Lukasz Pawelczyk, the raw capability calls are used rather
than the Smack wrapper that check addition restrictions.
In one case, as reported by Jann Horn, the wrong task is being
checked for capabilities.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Inform peer that IPv6 traffic has been blocked

In this patch we're sending an ICMPv6 message to a peer to
immediately inform it that making a connection is not possible.
In case of TCP connections, without this change, the peer
will be waiting until a connection timeout is exceeded.

Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Check UDP-Lite and DCCP protocols during IPv6 handling

The smack_socket_sock_rcv_skb() function is checking smack labels
only for UDP and TCP frames carried in IPv6 packets. From now on,
it is able also to handle UDP-Lite and DCCP protocols.

Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Fix handling of IPv4 traffic received by PF_INET6 sockets

A socket which has sk_family set to PF_INET6 is able to receive not
only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).

Prior to this patch, the smk_skb_to_addr_ipv6() could have been
called for socket buffers containing IPv4 packets, in result such
traffic was allowed.

Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

->file_open(): lose cred argument

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Smack: Mark inode instant in smack_task_to_inode

Smack: Mark inode instant in smack_task_to_inode

/proc clean-up in commit 1bbc55131e59bd099fdc568d3aa0b42634dbd188
resulted in smack_task_to_inode() being called before smack_d_instantiate.
This resulted in the smk_inode value being ignored, even while present
for files in /proc/self. Marking the inode as instant here fixes that.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

Smack: Fix memory leak in smack_inode_getsecctx

Fix memory leak in smack_inode_getsecctx

The implementation of smack_inode_getsecctx() made
incorrect assumptions about how Smack presents a security
context. Smack does not need to allocate memory to support
security contexts, so "releasing" a Smack context is a no-op.
The code made an unnecessary copy and returned that as a
context, which was never freed. The revised implementation
returns the context correctly.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: CHANDAN VN <chandan.vn@samsung.com>
Tested-by: CHANDAN VN <chandan.vn@samsung.com>

smack: provide socketpair callback

Make sure to implement the new socketpair callback so the SO_PEERSEC
call on socketpair(2)s will return correct information.

Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

ipc/msg: introduce msgctl(MSG_STAT_ANY)

There is a permission discrepancy when consulting msq ipc object
metadata between /proc/sysvipc/msg (0444) and the MSG_STAT shmctl
command. The later does permission checks for the object vs S_IRUGO.
As such there can be cases where EACCESS is returned via syscall but the
info is displayed anyways in the procfs files.

While this might have security implications via info leaking (albeit no
writing to the msq metadata), this behavior goes way back and showing
all the objects regardless of the permissions was most likely an
overlook - so we are stuck with it. Furthermore, modifying either the
syscall or the procfs file can cause userspace programs to break (ie
ipcs). Some applications require getting the procfs info (without root
privileges) and can be rather slow in comparison with a syscall -- up to
500x in some reported cases for shm.

This patch introduces a new MSG_STAT_ANY command such that the msq ipc
object permissions are ignored, and only audited instead. In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.

Link: http://lkml.kernel.org/r/20180215162458.10059-4-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Robert Kettler <robert.kettler@outlook.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/sem: introduce semctl(SEM_STAT_ANY)

There is a permission discrepancy when consulting shm ipc object
metadata between /proc/sysvipc/sem (0444) and the SEM_STAT semctl
command. The later does permission checks for the object vs S_IRUGO.
As such there can be cases where EACCESS is returned via syscall but the
info is displayed anyways in the procfs files.

While this might have security implications via info leaking (albeit no
writing to the sma metadata), this behavior goes way back and showing
all the objects regardless of the permissions was most likely an
overlook - so we are stuck with it. Furthermore, modifying either the
syscall or the procfs file can cause userspace programs to break (ie
ipcs). Some applications require getting the procfs info (without root
privileges) and can be rather slow in comparison with a syscall -- up to
500x in some reported cases for shm.

This patch introduces a new SEM_STAT_ANY command such that the sem ipc
object permissions are ignored, and only audited instead. In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.

Link: http://lkml.kernel.org/r/20180215162458.10059-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Robert Kettler <robert.kettler@outlook.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/shm: introduce shmctl(SHM_STAT_ANY)

Patch series "sysvipc: introduce STAT_ANY commands", v2.

The following patches adds the discussed (see [1]) new command for shm
as well as for sems and msq as they are subject to the same
discrepancies for ipc object permission checks between the syscall and
via procfs. These new commands are justified in that (1) we are stuck
with this semantics as changing syscall and procfs can break userland;
and (2) some users can benefit from performance (for large amounts of
shm segments, for example) from not having to parse the procfs
interface.

Once merged, I will submit the necesary manpage updates. But I'm thinking
something like:

: diff --git a/man2/shmctl.2 b/man2/shmctl.2
: index 7bb503999941..bb00bbe21a57 100644
: --- a/man2/shmctl.2
: +++ b/man2/shmctl.2
: @@ -41,6 +41,7 @@
: .\" 2005-04-25, mtk -- noted aberrant Linux behavior w.r.t. new
: .\" attaches to a segment that has already been marked for deletion.
: .\" 2005-08-02, mtk: Added IPC_INFO, SHM_INFO, SHM_STAT descriptions.
: +.\" 2018-02-13, dbueso: Added SHM_STAT_ANY description.
: .\"
: .TH SHMCTL 2 2017-09-15 "Linux" "Linux Programmer's Manual"
: .SH NAME
: @@ -242,6 +243,18 @@ However, the
: argument is not a segment identifier, but instead an index into
: the kernel's internal array that maintains information about
: all shared memory segments on the system.
: +.TP
: +.BR SHM_STAT_ANY " (Linux-specific)"
: +Return a
: +.I shmid_ds
: +structure as for
: +.BR SHM_STAT .
: +However, the
: +.I shm_perm.mode
: +is not checked for read access for
: +.IR shmid ,
: +resembing the behaviour of
: +/proc/sysvipc/shm.
: .PP
: The caller can prevent or allow swapping of a shared
: memory segment with the following \fIcmd\fP values:
: @@ -287,7 +300,7 @@ operation returns the index of the highest used entry in the
: kernel's internal array recording information about all
: shared memory segments.
: (This information can be used with repeated
: -.B SHM_STAT
: +.B SHM_STAT/SHM_STAT_ANY
: operations to obtain information about all shared memory segments
: on the system.)
: A successful
: @@ -328,7 +341,7 @@ isn't accessible.
: \fIshmid\fP is not a valid identifier, or \fIcmd\fP
: is not a valid command.
: Or: for a
: -.B SHM_STAT
: +.B SHM_STAT/SHM_STAT_ANY
: operation, the index value specified in
: .I shmid
: referred to an array slot that is currently unused.

This patch (of 3):

There is a permission discrepancy when consulting shm ipc object metadata
between /proc/sysvipc/shm (0444) and the SHM_STAT shmctl command. The
later does permission checks for the object vs S_IRUGO. As such there can
be cases where EACCESS is returned via syscall but the info is displayed
anyways in the procfs files.

While this might have security implications via info leaking (albeit no
writing to the shm metadata), this behavior goes way back and showing all
the objects regardless of the permissions was most likely an overlook - so
we are stuck with it. Furthermore, modifying either the syscall or the
procfs file can cause userspace programs to break (ie ipcs). Some
applications require getting the procfs info (without root privileges) and
can be rather slow in comparison with a syscall -- up to 500x in some
reported cases.

This patch introduces a new SHM_STAT_ANY command such that the shm ipc
object permissions are ignored, and only audited instead. In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.

[1] https://lkml.org/lkml/2017/12/19/220

Link: http://lkml.kernel.org/r/20180215162458.10059-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Robert Kettler <robert.kettler@outlook.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/smack: Tidy up from the change in type of the ipc security hooks

Rename the variables shp, sma, msq to isp. As that is how the code already
refers to those variables.

Collapse smack_of_shm, smack_of_sem, and smack_of_msq into smack_of_ipc,
as the three functions had become completely identical.

Collapse smack_shm_alloc_security, smack_sem_alloc_security and
smack_msg_queue_alloc_security into smack_ipc_alloc_security as the three
functions had become identical.

Collapse smack_shm_free_security, smack_sem_free_security and
smack_msg_queue_free_security into smack_ipc_free_security as the
three functions had become identical.

Requested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

security: Add a cred_getsecid hook

For IMA purposes, we want to be able to obtain the prepared secid in the
bprm structure before the credentials are committed. Add a cred_getsecid
hook that makes this possible.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooks

All of the implementations of security hooks that take msg_queue only
access q_perm the struct kern_ipc_perm member. This means the
dependencies of the msg_queue security hooks can be simplified by
passing the kern_ipc_perm member of msg_queue.

Making this change will allow struct msg_queue to become private to
ipc/msg.c.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks

All of the implementations of security hooks that take shmid_kernel only
access shm_perm the struct kern_ipc_perm member. This means the
dependencies of the shm security hooks can be simplified by passing
the kern_ipc_perm member of shmid_kernel..

Making this change will allow struct shmid_kernel to become private to ipc/shm.c.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks

All of the implementations of security hooks that take sem_array only
access sem_perm the struct kern_ipc_perm member. This means the
dependencies of the sem security hooks can be simplified by passing
the kern_ipc_perm member of sem_array.

Making this change will allow struct sem and struct sem_array
to become private to ipc/sem.c.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill

commit d178bc3a708f39cbfefc3fab37032d3f2511b4ec ("user namespace: usb:
make usb urbs user namespace aware (v2)") changed kill_pid_info_as_uid
to kill_pid_info_as_cred, saving and passing a cred structure instead of
uids. Since the secid can be obtained from the cred, drop the secid fields
from the usb_dev_state and async structures, and drop the secid argument to
kill_pid_info_as_cred. Replace the secid argument to security_task_kill
with the cred. Update SELinux, Smack, and AppArmor to use the cred, which
avoids the need for Smack and AppArmor to use a secid at all in this hook.
Further changes to Smack might still be required to take full advantage of
this change, since it should now be possible to perform capability
checking based on the supplied cred. The changes to Smack and AppArmor
have only been compile-tested.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

Smack: Handle CGROUP2 in the same way that CGROUP

The new file system CGROUP2 isn't actually handled
by smack. This changes makes Smack treat equally
CGROUP and CGROUP2 items.

Signed-off-by: José Bollo <jose.bollo@iot.bzh>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Privilege check on key operations

Smack: Privilege check on key operations

Operations on key objects are subjected to Smack policy
even if the process is privileged. This is inconsistent
with the general behavior of Smack and may cause issues
with authentication by privileged daemons. This patch
allows processes with CAP_MAC_OVERRIDE to access keys
even if the Smack rules indicate otherwise.

Reported-by: Jose Bollo <jobol@nonadev.net>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: fix dereferenced before check

This patch fixes the warning reported by smatch:
security/smack/smack_lsm.c:2872 smack_socket_connect() warn:
variable dereferenced before check 'sock->sk' (see line 2869)

Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Base support for overlayfs

Supply the Smack module hooks in support of overlayfs.
Ensure that the Smack label of new files gets the correct
value when a directory is transmuting. Original implementation
by Romanini Daniele, with a few tweaks added.

Signed-off-by: Romanini Daniele <daniele.romanini@aalto.fi>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

lsm: fix smack_inode_removexattr and xattr_getsecurity memleak

security_inode_getsecurity() provides the text string value
of a security attribute. It does not provide a "secctx".
The code in xattr_getsecurity() that calls security_inode_getsecurity()
and then calls security_release_secctx() happened to work because
SElinux and Smack treat the attribute and the secctx the same way.
It fails for cap_inode_getsecurity(), because that module has no
secctx that ever needs releasing. It turns out that Smack is the
one that's doing things wrong by not allocating memory when instructed
to do so by the "alloc" parameter.

The fix is simple enough. Change the security_release_secctx() to
kfree() because it isn't a secctx being returned by
security_inode_getsecurity(). Change Smack to allocate the string when
told to do so.

Note: this also fixes memory leaks for LSMs which implement
inode_getsecurity but not release_secctx, such as capabilities.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>

smack: Remove redundant pdeath_signal clearing

This removes the redundant pdeath_signal clearing in Smack: the check in
smack_bprm_committing_creds() matches the check in smack_bprm_set_creds()
(which used to be in the now-removed smack_bprm_securexec() hook) and
since secureexec is now being checked for clearing pdeath_signal, this
is redundant to the common exec code.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Refactor to remove bprm_secureexec hook

The Smack bprm_secureexec hook can be merged with the bprm_set_creds
hook since it's dealing with the same information, and all of the details
are finalized during the first call to the bprm_set_creds hook via
prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored
via bprm->called_set_creds).

Here, the test can just happen at the end of the bprm_set_creds hook,
and the bprm_secureexec hook can be dropped.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>

exec: Rename bprm->cred_prepared to called_set_creds

The cred_prepared bprm flag has a misleading name. It has nothing to do
with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has
been called. Rename this flag and improve its comment.

Cc: David Howells <dhowells@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Serge Hallyn <serge@hallyn.com>

Smack: Safer check for a socket in file_receive

The check of S_ISSOCK() in smack_file_receive() is not
appropriate if the passed descriptor is a socket.

Reported-by: Stephen Smalley <sds@tyco.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: fix double free in smack_parse_opts_str()

smack_parse_opts_str() calls kfree(opts->mnt_opts) when kcalloc() for
opts->mnt_opts_flags failed. But it should not have called it because
security_free_mnt_opts() will call kfree(opts->mnt_opts).

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
fixes: 3bf2789cad9e6573 ("smack: allow mount opts setting over filesystems with binary mount data")
Cc: Vivek Trivedi <t.vivek@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>

security: mark LSM hooks as __ro_after_init

Mark all of the registration hooks as __ro_after_init (via the
__lsm_ro_after_init macro).

Signed-off-by: James Morris <james.l.morris@oracle.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Kees Cook <keescook@chromium.org>

exec: Remove LSM_UNSAFE_PTRACE_CAP

With previous changes every location that tests for
LSM_UNSAFE_PTRACE_CAP also tests for LSM_UNSAFE_PTRACE making the
LSM_UNSAFE_PTRACE_CAP redundant, so remove it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

LSM: Add /sys/kernel/security/lsm

I am still tired of having to find indirect ways to determine
what security modules are active on a system. I have added
/sys/kernel/security/lsm, which contains a comma separated
list of the active security modules. No more groping around
in /proc/filesystems or other clever hacks.

Unchanged from previous versions except for being updated
to the latest security next branch.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>

security,selinux,smack: kill security_task_wait hook

As reported by yangshukui, a permission denial from security_task_wait()
can lead to a soft lockup in zap_pid_ns_processes() since it only expects
sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can
in general lead to zombies; in the absence of some way to automatically
reparent a child process upon a denial, the hook is not useful. Remove
the security hook and its implementations in SELinux and Smack. Smack
already removed its check from its hook.

Reported-by: yangshukui <yangshukui@huawei.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Smack: ignore private inode for file functions

The access to fd from anon_inode is always failed because there is
no set xattr operations. So this patch fixes to ignore private
inode including anon_inode for file functions.

It was only ignored for smack_file_receive() to share dma-buf fd,
but dma-buf has other functions like ioctl and mmap.

Reference: https://lkml.org/lkml/2015/4/17/16

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: fix d_instantiate logic for sockfs and pipefs

Since 4b936885a (v2.6.32) all inodes on sockfs and pipefs are disconnected.
It caused filesystem specific code in smack_d_instantiate to be skipped,
because all inodes on those pseudo filesystems were treated as root inodes.
As a result all sockfs inodes had the Smack label set to floor.

In most cases access checks for sockets use socket_smack data so the inode
label is not important. But there are special cases that were broken.
One example would be calling fcntl with F_SETOWN command on a socket fd.

Now smack_d_instantiate expects all pipefs and sockfs inodes to be
disconnected and has the logic in appropriate place.

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Use smk_tskacc() instead of smk_access() for proper logging

smack_file_open() is first checking the capability of calling subject,
this check will skip the SMACK logging for success case. Use smk_tskacc()
for proper logging and SMACK access check.

Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Traverse the smack_known_list using list_for_each_entry_rcu macro

In smack_from_secattr function,"smack_known_list" is being traversed
using list_for_each_entry macro, although it is a rcu protected
structure. So it should be traversed using "list_for_each_entry_rcu"
macro to fetch the rcu protected entry.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Free the i_security blob in inode using RCU

There is race condition issue while freeing the i_security blob in SMACK
module. There is existing condition where i_security can be freed while
inode_permission is called from path lookup on second CPU. There has been
observed the page fault with such condition. VFS code and Selinux module
takes care of this condition by freeing the inode and i_security field
using RCU via call_rcu(). But in SMACK directly the i_secuirty blob is
being freed. Use call_rcu() to fix this race condition issue.

Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Delete list_head repeated initialization

smk_copy_rules() and smk_copy_relabel() are initializing list_head though
they have been initialized already in new_task_smack() function. Delete
repeated initialization.

Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Fix the issue of wrong SMACK label update in socket bind fail case

Fix the issue of wrong SMACK label (SMACK64IPIN) update when a second bind
call is made to same IP address & port, but with different SMACK label
(SMACK64IPIN) by second instance of server. In this case server returns
with "Bind:Address already in use" error but before returning, SMACK label
is updated in SMACK port-label mapping list inside smack_socket_bind() hook

To fix this issue a new check has been added in smk_ipv6_port_label()
function before updating the existing port entry. It checks whether the
socket for matching port entry is closed or not. If it is closed then it
means port is not bound and it is safe to update the existing port entry
else return if port is still getting used. For checking whether socket is
closed or not, one more field "smk_can_reuse" has been added in the
"smk_port_label" structure. This field will be set to '1' in
"smack_sk_free_security()" function which is called to free the socket
security blob when the socket is being closed. In this function, port entry
is searched in the SMACK port-label mapping list for the closing socket.
If entry is found then "smk_can_reuse" field is set to '1'.Initially
"smk_can_reuse" field is set to '0' in smk_ipv6_port_label() function after
creating a new entry in the list which indicates that socket is in use.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Fix the issue of permission denied error in ipv6 hook

Permission denied error comes when 2 IPv6 servers are running and client
tries to connect one of them. Scenario is that both servers are using same
IP and port but different protocols(Udp and tcp). They are using different
SMACK64IPIN labels.Tcp server is using "test" and udp server is using
"test-in". When we try to run tcp client with SMACK64IPOUT label as "test",
then connection denied error comes. It should not happen since both tcp
server and client labels are same.This happens because there is no check
for protocol in smk_ipv6_port_label() function while searching for the
earlier port entry. It checks whether there is an existing port entry on
the basis of port only. So it updates the earlier port entry in the list.
Due to which smack label gets changed for earlier entry in the
"smk_ipv6_port_list" list and permission denied error comes.

Now a check is added for socket type also.Now if 2 processes use same
port but different protocols (tcp or udp), then 2 different port entries
will be added in the list. Similarly while checking smack access in
smk_ipv6_port_check() function, port entry is searched on the basis of
both port and protocol.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Himanshu Shukla <Himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Add the rcu synchronization mechanism in ipv6 hooks

Add the rcu synchronization mechanism for accessing smk_ipv6_port_list
in smack IPv6 hooks. Access to the port list is vulnerable to a race
condition issue,it does not apply proper synchronization methods while
working on critical section. It is possible that when one thread is
reading the list, at the same time another thread is modifying the
same port list, which can cause the major problems.

To ensure proper synchronization between two threads, rcu mechanism
has been applied while accessing and modifying the port list. RCU will
also not affect the performance, as there are more accesses than
modification where RCU is most effective synchronization mechanism.

Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

proc,security: move restriction on writing /proc/pid/attr nodes to proc

Processes can only alter their own security attributes via
/proc/pid/attr nodes. This is presently enforced by each individual
security module and is also imposed by the Linux credentials
implementation, which only allows a task to alter its own credentials.
Move the check enforcing this restriction from the individual
security modules to proc_pid_attr_write() before calling the security hook,
and drop the unnecessary task argument to the security hook since it can
only ever be the current task.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

don't open-code file_inode()

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

Smack: Remove unnecessary smack_known_invalid

The invalid Smack label ("") and the Huh ("?") Smack label
serve the same purpose and having both is unnecessary.
While pulling out the invalid label it became clear that
the use of smack_from_secid() was inconsistent, so that
is repaired. The setting of inode labels to the invalid
label could never happen in a functional system, has
never been observed in the wild and is not what you'd
really want for a failure behavior in any case. That is
removed.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Use GFP_KERNEL for smack_parse_opts_str().

Since smack_parse_opts_str() is calling match_strdup() which uses
GFP_KERNEL, it is safe to use GFP_KERNEL from kcalloc() which is
called by smack_parse_opts_str().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: ipv6 label match fix

The check for a deleted entry in the list of IPv6 host
addresses was being performed in the wrong place, leading
to most peculiar results in some cases. This puts the
check into the right place.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Fix the memory leak in smack_cred_prepare() hook

Memory leak in smack_cred_prepare()function.
smack_cred_prepare() hook returns error if there is error in allocating
memory in smk_copy_rules() or smk_copy_relabel() function.
If smack_cred_prepare() function returns error then the calling
function should call smack_cred_free() function for cleanup.
In smack_cred_free() function first credential is extracted and
then all rules are deleted. In smack_cred_prepare() function security
field is assigned in the end when all function return success. But this
function may return before and memory will not be freed.

Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Do not apply star label in smack_setprocattr hook

Smack prohibits processes from using the star ("*") and web ("@") labels.
Checks have been added in other functions. In smack_setprocattr()
hook, only check for web ("@") label has been added and restricted
from applying web ("@") label.
Check for star ("*") label should also be added in smack_setprocattr()
hook. Return error should be "-EINVAL" not "-EPERM" as permission
is there for setting label but not the label value as star ("*") or
web ("@").

Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

smack: parse mnt opts after privileges check

In smack_set_mnt_opts()first the SMACK mount options are being
parsed and later it is being checked whether the user calling
mount has CAP_MAC_ADMIN capability.
This sequence of operationis will allow unauthorized user to add
SMACK labels in label list and may cause denial of security attack
by adding many labels by allocating kernel memory by unauthorized user.
Superblock smack flag is also being set as initialized though function
may return with EPERM error.
First check the capability of calling user then set the SMACK attributes
and smk_flags.

Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Assign smack_known_web label for kernel thread's

Assign smack_known_web label for kernel thread's socket

Creating struct sock by sk_alloc function in various kernel subsystems
like bluetooth doesn't call smack_socket_post_create(). In such case,
received sock label is the floor('_') label and makes access deny.

Signed-off-by: jooseong lee <jooseong.lee@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

xattr: Add __vfs_{get,set,remove}xattr helpers

Right now, various places in the kernel check for the existence of
getxattr, setxattr, and removexattr inode operations and directly call
those operations. Switch to helper functions and test for the IOP_XATTR
flag instead.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Smack: Signal delivery as an append operation

Under a strict subject/object security policy delivering a
signal or delivering network IPC could be considered either
a write or an append operation. The original choice to make
both write operations leads to an issue where IPC delivery
is desired under policy, but delivery of signals is not.
This patch provides the option of making signal delivery
an append operation, allowing Smack rules that deny signal
delivery while allowing IPC. This was requested for Tizen.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

netlabel: Pass a family parameter to netlbl_skbuff_err().

This makes it possible to route the error to the appropriate
labelling engine. CALIPSO is far less verbose than CIPSO
when encountering a bogus packet, so there is no need for a
CALIPSO error handler.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Smack: Handle labels consistently in untrusted mounts

The SMACK64, SMACK64EXEC, and SMACK64MMAP labels are all handled
differently in untrusted mounts. This is confusing and
potentically problematic. Change this to handle them all the same
way that SMACK64 is currently handled; that is, read the label
from disk and check it at use time. For SMACK64 and SMACK64MMAP
access is denied if the label does not match smk_root. To be
consistent with suid, a SMACK64EXEC label which does not match
smk_root will still allow execution of the file but will not run
with the label supplied in the xattr.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Smack: Add support for unprivileged mounts from user namespaces

Security labels from unprivileged mounts cannot be trusted.
Ideally for these mounts we would assign the objects in the
filesystem the same label as the inode for the backing device
passed to mount. Unfortunately it's currently impossible to
determine which inode this is from the LSM mount hooks, so we
settle for the label of the process doing the mount.

This label is assigned to s_root, and also to smk_default to
ensure that new inodes receive this label. The transmute property
is also set on s_root to make this behavior more explicit, even
though it is technically not necessary.

If a filesystem has existing security labels, access to inodes is
permitted if the label is the same as smk_root, otherwise access
is denied. The SMACK64EXEC xattr is completely ignored.

Explicit setting of security labels continues to require
CAP_MAC_ADMIN in init_user_ns.

Altogether, this ensures that filesystem objects are not
accessible to subjects which cannot already access the backing
store, that MAC is not violated for any objects in the fileystem
which are already labeled, and that a user cannot use an
unprivileged mount to gain elevated MAC privileges.

sysfs, tmpfs, and ramfs are already mountable from user
namespaces and support security labels. We can't rule out the
possibility that these filesystems may already be used in mounts
from user namespaces with security lables set from the init
namespace, so failing to trust lables in these filesystems may
introduce regressions. It is safe to trust labels from these
filesystems, since the unprivileged user does not control the
backing store and thus cannot supply security labels, so an
explicit exception is made to trust labels from these
filesystems.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Smack: ignore null signal in smack_task_kill

Kill with signal number 0 is commonly used for checking PID existence.
Smack treated such cases like any other kills, although no signal is
actually delivered when sig == 0.

Checking permissions when sig == 0 didn't prevent an unprivileged caller
from learning whether PID exists or not. When it existed, kernel returned
EPERM, when it didn't - ESRCH. The only effect of policy check in such
case is noise in audit logs.

This change lets Smack silently ignore kill() invocations with sig == 0.

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

switch ->setxattr() to passing dentry and inode separately

smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.

Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

->getxattr(): pass dentry and inode as separate arguments

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

don't bother with ->d_inode->i_sb - it's always equal to ->d_sb

... and neither can ever be NULL

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

smack: fix cache of access labels

Before this commit, removing the access property of
a file, aka, the extended attribute security.SMACK64
was not effictive until the cache had been cleaned.

This patch fixes that problem.

Signed-off-by: José Bollo <jobol@nonadev.net>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Remove pointless hooks

Prior to the 4.2 kernel there no no harm in providing
a security module hook that does nothing, as the default
hook would get called if the module did not supply one.
With the list based infrastructure an empty hook adds
overhead. This patch removes the three Smack hooks that
don't actually do anything.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security: let security modules use PTRACE_MODE_* with bitmasks

It looks like smack and yama weren't aware that the ptrace mode
can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but
only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch,
all modes have flags ORed into them.

Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security: Make inode argument of inode_getsecid non-const

Make the inode argument of the inode_getsecid hook non-const so that we
can use it to revalidate invalid security labels.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

security: Make inode argument of inode_getsecurity non-const

Make the inode argument of the inode_getsecurity hook non-const so that
we can use it to revalidate invalid security labels.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>

Smack: type confusion in smak sendmsg() handler

Smack security handler for sendmsg() syscall
is vulnerable to type confusion issue what
can allow to privilege escalation into root
or cause denial of service.

A malicious attacker can create socket of one
type for example AF_UNIX and pass is into
sendmsg() function ensuring that this is
AF_INET socket.

Remedy
Do not trust user supplied data.
Proposed fix below.

Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Signed-off-by: Mateusz Fruba <m.fruba@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

nfs: Move call to security_inode_listsecurity into nfs_listxattr

Add a nfs_listxattr operation. Move the call to security_inode_listsecurity
from list operation of the "security.*" xattr handler to nfs_listxattr.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Smack: File receive for sockets

The existing file receive hook checks for access on
the file inode even for UDS. This is not right, as
the inode is not used by Smack to make access checks
for sockets. This change checks for an appropriate
access relationship between the receiving (current)
process and the socket. If the process can't write
to the socket's send label or the socket's receive
label can't write to the process fail.

This will allow the legitimate cases, where the
socket sender and socket receiver can freely communicate.
Only strangly set socket labels should cause a problem.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: limited capability for changing process label

This feature introduces new kernel interface:

- <smack_fs>/relabel-self - for setting transition labels list

This list is used to control smack label transition mechanism.
List is set by, and per process. Process can transit to new label only if
label is on the list. Only process with CAP_MAC_ADMIN capability can add
labels to this list. With this list, process can change it's label without
CAP_MAC_ADMIN but only once. After label changing, list is unset.

Changes in v2:
* use list_for_each_entry instead of _rcu during label write
* added missing description in security/Smack.txt

Changes in v3:
* squashed into one commit

Changes in v4:
* switch from global list to per-task list
* since the per-task list is accessed only by the task itself
there is no need to use synchronization mechanisms on it

Changes in v5:
* change smackfs interface of relabel-self to the one used for onlycap
multiple labels are accepted, separated by space, which
replace the previous list upon write

Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: pipefs fix in smack_d_instantiate

This fix writes the task label when
smack_d_instantiate is called, before the
label of the superblock was written on the
pipe's inode.

Signed-off-by: Roman Kubiak <r.kubiak@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Minor initialisation improvement

This change has two goals:
- delay the setting of 'smack_enabled' until
it will be really effective
- ensure that smackfs is valid only if 'smack_enabled'
is set (it is already the case in smack_netfilter.c)

Signed-off-by: José Bollo <jose.bollo@iot.bzh>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

smack: smk_ipv6_port_list should be static

Fixes the following sparse warning:

security/smack/smack_lsm.c:55:1: warning: symbol 'smk_ipv6_port_list'
was not declared. Should it be static?

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

Smack - Fix build error with bringup unconfigured

The changes for mounting binary filesystems was allied
improperly, with the list of tokens being in an ifdef that
it shouldn't have been. Fix that, and a couple style issues
that were bothering me.

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Three symbols that should be static

The kbuild test robot reported a couple of these,
and the third showed up by inspection. Making the
symbols static is proper.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: IPv6 host labeling

IPv6 appears to be (finally) coming of age with the
influx of autonomous devices. In support of this, add
the ability to associate a Smack label with IPv6 addresses.

This patch also cleans up some of the conditional
compilation associated with the introduction of
secmark processing. It's now more obvious which bit
of code goes with which feature.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: allow mount opts setting over filesystems with binary mount data

Add support for setting smack mount labels(using smackfsdef, smackfsroot,
smackfshat, smackfsfloor, smackfstransmute) for filesystems with binary
mount data like NFS.

To achieve this, implement sb_parse_opts_str and sb_set_mnt_opts security
operations in smack LSM similar to SELinux.

Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

smack: pass error code through pointers

This patch makes the following functions to use ERR_PTR() and related
macros to pass the appropriate error code through returned pointers:

smk_parse_smack()
smk_import_entry()
smk_fetch()

It also makes all the other functions that use them to handle the
error cases properly. This ways correct error codes from places
where they happened can be propagated to the user space if necessary.

Doing this it fixes a bug in onlycap and unconfined files
handling. Previously their content was cleared on any error from
smk_import_entry/smk_parse_smack, be it EINVAL (as originally intended)
or ENOMEM. Right now it only reacts on EINVAL passing other codes
properly to userspace.

Comments have been updated accordingly.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

Smack: ignore private inode for smack_file_receive

The dmabuf fd can be shared between processes via unix domain
socket. The file of dmabuf fd is came from anon_inode. The inode
has no set and get xattr operations, so it can not be shared
between processes with smack. This patch fixes just to ignore
private inode including anon_inode for smack_file_receive.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>

LSM: Switch to lists of hooks

Instead of using a vector of security operations
with explicit, special case stacking of the capability
and yama hooks use lists of hooks with capability and
yama hooks included as appropriate.

The security_operations structure is no longer required.
Instead, there is a union of the function pointers that
allows all the hooks lists to use a common mechanism for
list management while retaining typing. Each module
supplies an array describing the hooks it provides instead
of a sparsely populated security_operations structure.
The description includes the element that gets put on
the hook list, avoiding the issues surrounding individual
element allocation.

The method for registering security modules is changed to
reflect the information available. The method for removing
a module, currently only used by SELinux, has also changed.
It should be generic now, however if there are potential
race conditions based on ordering of hook removal that needs
to be addressed by the calling module.

The security hooks are called from the lists and the first
failure is returned.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>

LSM: Add security module hook list heads

Add a list header for each security hook. They aren't used until
later in the patch series. They are grouped together in a structure
so that there doesn't need to be an external address for each.

Macro-ize the initialization of the security_operations
for each security module in anticipation of changing out
the security_operations structure.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>

VFS: security/: d_backing_inode() annotations

most of the ->d_inode uses there refer to the same inode IO would
go to, i.e. d_backing_inode()

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

switch security_inode_getattr() to struct path *

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

Smack: Allow an unconfined label in bringup mode

I have vehemently opposed adding a "permissive" mode to Smack
for the simple reasons that it would be subject to massive abuse
and that developers refuse to turn it off come product release.
I still believe that this is true, and still refuse to add a
general "permissive mode". So don't ask again.

Bumjin Im suggested an approach that addresses most of the concerns,
and I have implemented it here. I still believe that we'd be better
off without this sort of thing, but it looks like this minimizes the
abuse potential.

Firstly, you have to configure Smack Bringup Mode. That allows
for "release" software to be ammune from abuse. Second, only one
label gets to be "permissive" at a time. You can use it for
debugging, but that's about it.

A label written to smackfs/unconfined is treated specially.
If either the subject or object label of an access check
matches the "unconfined" label, and the access would not
have been allowed otherwise an audit record and a console
message are generated. The audit record "request" string is
marked with either "(US)" or "(UO)", to indicate that the
request was granted because of an unconfined label. The
fact that an inode was accessed by an unconfined label is
remembered, and subsequent accesses to that "impure"
object are noted in the log. The impurity is not stored in
the filesystem, so a file mislabled as a side effect of
using an unconfined label may still cause concern after
a reboot.

So, it's there, it's dangerous, but so many application
developers seem incapable of living without it I have
given in. I've tried to make it as safe as I can, but
in the end it's still a chain saw.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: getting the Smack security context of keys

With this commit, the LSM Smack implements the LSM
side part of the system call keyctl with the action
code KEYCTL_GET_SECURITY.

It is now possible to get the context of, for example,
the user session key using the command "keyctl security @s".

The original patch has been modified for merge.

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Assign smack_known_web as default smk_in label for kernel thread's socket

This change fixes the bug associated with sockets owned by kernel threads. These
sockets, created usually by network devices' drivers tasks, received smk_in
label from the task that created them - the "floor" label in the most cases. The
result was that they were not able to receive data packets because of missing
smack rules. The main reason of the access deny is that the socket smk_in label
is placed as the object during smk check, kernel thread's capabilities are
omitted.

Signed-off-by: Marcin Lis <m.lis@samsung.com>

Smack: Use d_is_positive() rather than testing dentry->d_inode

Use d_is_positive() rather than testing dentry->d_inode in Smack to get rid of
direct references to d_inode outside of the VFS.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Smack: secmark connections

If the secmark is available us it on connection as
well as packet delivery.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: fix possible use after frees in task_security() callers

We hit use after free on dereferncing pointer to task_smack struct in
smk_of_task() called from smack_task_to_inode().

task_security() macro uses task_cred_xxx() to get pointer to the task_smack.
task_cred_xxx() could be used only for non-pointer members of task's
credentials. It cannot be used for pointer members since what they point
to may disapper after dropping RCU read lock.

Mainly task_security() used this way:
smk_of_task(task_security(p))

Intead of this introduce function smk_of_task_struct() which
takes task_struct as argument and returns pointer to smk_known struct
and do this under RCU read lock.
Bogus task_security() macro is not used anymore, so remove it.

KASan's report for this:

AddressSanitizer: use after free in smack_task_to_inode+0x50/0x70 at addr c4635600
=============================================================================
BUG kmalloc-64 (Tainted: PO): kasan error
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Allocated in new_task_smack+0x44/0xd8 age=39 cpu=0 pid=1866
kmem_cache_alloc_trace+0x88/0x1bc
new_task_smack+0x44/0xd8
smack_cred_prepare+0x48/0x21c
security_prepare_creds+0x44/0x4c
prepare_creds+0xdc/0x110
smack_setprocattr+0x104/0x150
security_setprocattr+0x4c/0x54
proc_pid_attr_write+0x12c/0x194
vfs_write+0x1b0/0x370
SyS_write+0x5c/0x94
ret_fast_syscall+0x0/0x48
INFO: Freed in smack_cred_free+0xc4/0xd0 age=27 cpu=0 pid=1564
kfree+0x270/0x290
smack_cred_free+0xc4/0xd0
security_cred_free+0x34/0x3c
put_cred_rcu+0x58/0xcc
rcu_process_callbacks+0x738/0x998
__do_softirq+0x264/0x4cc
do_softirq+0x94/0xf4
irq_exit+0xbc/0x120
handle_IRQ+0x104/0x134
gic_handle_irq+0x70/0xac
__irq_svc+0x44/0x78
_raw_spin_unlock+0x18/0x48
sync_inodes_sb+0x17c/0x1d8
sync_filesystem+0xac/0xfc
vdfs_file_fsync+0x90/0xc0
vfs_fsync_range+0x74/0x7c
INFO: Slab 0xd3b23f50 objects=32 used=31 fp=0xc4635600 flags=0x4080
INFO: Object 0xc4635600 @offset=5632 fp=0x (null)

Bytes b4 c46355f0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Object c4635600: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object c4635610: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object c4635620: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object c4635630: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
Redzone c4635640: bb bb bb bb ....
Padding c46356e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding c46356f8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
CPU: 5 PID: 834 Comm: launchpad_prelo Tainted: PBO 3.10.30 #1
Backtrace:
[<c00233a4>] (dump_backtrace+0x0/0x158) from [<c0023dec>] (show_stack+0x20/0x24)
r7:c4634010 r6:d3b23f50 r5:c4635600 r4:d1002140
[<c0023dcc>] (show_stack+0x0/0x24) from [<c06d6d7c>] (dump_stack+0x20/0x28)
[<c06d6d5c>] (dump_stack+0x0/0x28) from [<c01c1d50>] (print_trailer+0x124/0x144)
[<c01c1c2c>] (print_trailer+0x0/0x144) from [<c01c1e88>] (object_err+0x3c/0x44)
r7:c4635600 r6:d1002140 r5:d3b23f50 r4:c4635600
[<c01c1e4c>] (object_err+0x0/0x44) from [<c01cac18>] (kasan_report_error+0x2b8/0x538)
r6:d1002140 r5:d3b23f50 r4:c6429cf8 r3:c09e1aa7
[<c01ca960>] (kasan_report_error+0x0/0x538) from [<c01c9430>] (__asan_load4+0xd4/0xf8)
[<c01c935c>] (__asan_load4+0x0/0xf8) from [<c031e168>] (smack_task_to_inode+0x50/0x70)
r5:c4635600 r4:ca9da000
[<c031e118>] (smack_task_to_inode+0x0/0x70) from [<c031af64>] (security_task_to_inode+0x3c/0x44)
r5:cca25e80 r4:c0ba9780
[<c031af28>] (security_task_to_inode+0x0/0x44) from [<c023d614>] (pid_revalidate+0x124/0x178)
r6:00000000 r5:cca25e80 r4:cbabe3c0 r3:00008124
[<c023d4f0>] (pid_revalidate+0x0/0x178) from [<c01db98c>] (lookup_fast+0x35c/0x43y4)
r9:c6429efc r8:00000101 r7:c079d940 r6:c6429e90 r5:c6429ed8 r4:c83c4148
[<c01db630>] (lookup_fast+0x0/0x434) from [<c01deec8>] (do_last.isra.24+0x1c0/0x1108)
[<c01ded08>] (do_last.isra.24+0x0/0x1108) from [<c01dff04>] (path_openat.isra.25+0xf4/0x648)
[<c01dfe10>] (path_openat.isra.25+0x0/0x648) from [<c01e1458>] (do_filp_open+0x3c/0x88)
[<c01e141c>] (do_filp_open+0x0/0x88) from [<c01ccb28>] (do_sys_open+0xf0/0x198)
r7:00000001 r6:c0ea2180 r5:0000000b r4:00000000
[<c01cca38>] (do_sys_open+0x0/0x198) from [<c01ccc00>] (SyS_open+0x30/0x34)
[<c01ccbd0>] (SyS_open+0x0/0x34) from [<c001db80>] (ret_fast_syscall+0x0/0x48)
Read of size 4 by thread T834:
Memory state around the buggy address:
c4635380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c4635400: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
c4635480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c4635500: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
c4635580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>c4635600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
c4635680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
c4635700: 00 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc
c4635780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c4635800: 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc fc
c4635880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: <stable@vger.kernel.org>

smack: Add missing logging in bidirectional UDS connect check

During UDS connection check, both sides are checked for write access to
the other side. But only the first check is performed with audit support.
The second one didn't produce any audit logs. This simple patch fixes that.

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>

Smack: secmark support for netfilter

Smack uses CIPSO to label internet packets and thus provide
for access control on delivery of packets. The netfilter facility
was not used to allow for Smack to work properly without netfilter
configuration. Smack does not need netfilter, however there are
cases where it would be handy.

As a side effect, the labeling of local IPv4 packets can be optimized
and the handling of local IPv6 packets is just all out better.

The best part is that the netfilter tools use "contexts" that
are just strings, and they work just as well for Smack as they
do for SELinux.

All of the conditional compilation for IPv6 was implemented
by Rafal Krypa <r.krypa@samsung.com>

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Rework file hooks

This is one of those cases where you look at code you did
years ago and wonder what you might have been thinking.
There are a number of LSM hooks that work off of file pointers,
and most of them really want the security data from the inode.
Some, however, really want the security context that the process
had when the file was opened. The difference went undetected in
Smack until it started getting used in a real system with real
testing. At that point it was clear that something was amiss.

This patch corrects the misuse of the f_security value in several
of the hooks. The behavior will not usually be any different, as
the process had to be able to open the file in the first place, and
the old check almost always succeeded, as will the new, but for
different reasons.

Thanks to the Samsung Tizen development team that identified this.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

smack: Fix a bidirectional UDS connect check typo

The 54e70ec5eb090193b03e69d551fa6771a5a217c4 commit introduced a
bidirectional check that should have checked for mutual WRITE access
between two labels. Due to a typo subject's OUT label is checked with
object's OUT. Should be OUT to IN.

Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>

smack: introduce a special case for tmpfs in smack_d_instantiate()

Files created with __shmem_file_stup() appear to have somewhat fake
dentries which make them look like root directories and not get
the label the current process or ("*") star meant for tmpfs files.

Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>

smack: fix logic in smack_inode_init_security function

In principle if this function was called with "value" == NULL and "len"
not NULL it could return different results for the "len" compared to a
case where "name" was not NULL. This is a hypothetical case that does
not exist in the kernel, but it's a logic bug nonetheless.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

smack: miscellaneous small fixes in function comments

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

assorted conversions to %p[dD]

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

Security: smack: replace kzalloc with kmem_cache for inode_smack

The patch use kmem_cache to allocate/free inode_smack since they are
alloced in high volumes making it a perfect case for kmem_cache.

As per analysis, 24 bytes of memory is wasted per allocation due
to internal fragmentation. With kmem_cache, this can be avoided.

Accounting of memory allocation is below :
total slack net count-alloc/free caller
Before (with kzalloc)
1919872 719952 1919872 29998/0 new_inode_smack+0x14

After (with kmem_cache)
1201680 0 1201680 30042/0 new_inode_smack+0x18

>From above data, we found that 719952 bytes(~700 KB) of memory is
saved on allocation of 29998 smack inodes.

Signed-off-by: Rohit <rohit.kr@samsung.com>

security: make security_file_set_fowner, f_setown and __f_setown void return

security_file_set_fowner always returns 0, so make it f_setown and
__f_setown void return functions and fix up the error handling in the
callers.

Cc: linux-security-module@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Make Smack operate on smack_known struct where it still used char*

Smack used to use a mix of smack_known struct and char* throughout its
APIs and implementation. This patch unifies the behaviour and makes it
store and operate exclusively on smack_known struct pointers when managing
labels.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

Conflicts:
security/smack/smack_access.c
security/smack/smack_lsm.c

Fix a bidirectional UDS connect check typo

The 54e70ec5eb090193b03e69d551fa6771a5a217c4 commit introduced a
bidirectional check that should have checked for mutual WRITE access
between two labels. Due to a typo the second check was incorrect.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

Small fixes in comments describing function parameters

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

Smack: Bring-up access mode

People keep asking me for permissive mode, and I keep saying "no".

Permissive mode is wrong for more reasons than I can enumerate,
but the compelling one is that it's once on, never off.

Nonetheless, there is an argument to be made for running a
process with lots of permissions, logging which are required,
and then locking the process down. There wasn't a way to do
that with Smack, but this provides it.

The notion is that you start out by giving the process an
appropriate Smack label, such as "ATBirds". You create rules
with a wide range of access and the "b" mode. On Tizen it
might be:

ATBirds System rwxalb
ATBirds User rwxalb
ATBirds _ rwxalb
User ATBirds wb
System ATBirds wb

Accesses that fail will generate audit records. Accesses
that succeed because of rules marked with a "b" generate
log messages identifying the rule, the program and as much
object information as is convenient.

When the system is properly configured and the programs
brought in line with the labeling scheme the "b" mode can
be removed from the rules. When the system is ready for
production the facility can be configured out.

This provides the developer the convenience of permissive
mode without creating a system that looks like it is
enforcing a policy while it is not.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Fix setting label on successful file open

While opening with CAP_MAC_OVERRIDE file label is not set.
Other calls may access it after CAP_MAC_OVERRIDE is dropped from process.

Signed-off-by: Marcin Niesluchowski <m.niesluchow@samsung.com>

Smack: remove unneeded NULL-termination from securtity label

Values of extended attributes are stored as binary blobs. NULL-termination
of them isn't required. It just wastes disk space and confuses command-line
tools like getfattr because they have to print that zero byte at the end.

This patch removes terminating zero byte from initial security label in
smack_inode_init_security and cuts it out in function smack_inode_getsecurity
which is used by syscall getxattr. This change seems completely safe, because
function smk_parse_smack ignores everything after first zero byte.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>

Smack: handle zero-length security labels without panic

Zero-length security labels are invalid but kernel should handle them.

This patch fixes kernel panic after setting zero-length security labels:
# attr -S -s "SMACK64" -V "" file

And after writing zero-length string into smackfs files syslog and onlycp:
# python -c 'import os; os.write(1, "")' > /smack/syslog

The problem is caused by brain-damaged logic in function smk_parse_smack()
which takes pointer to buffer and its length but if length below or equal zero
it thinks that the buffer is zero-terminated. Unfortunately callers of this
function are widely used and proper fix requires serious refactoring.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>

Smack: fix behavior of smack_inode_listsecurity

Security operation ->inode_listsecurity is used for generating list of
available extended attributes for syscall listxattr. Currently it's used
only in nfs4 or if filesystem doesn't provide i_op->listxattr.

The list is the set of NULL-terminated names, one after the other.
This method must include zero byte at the and into result.

Also this function must return length even if string does not fit into
output buffer or it is NULL, see similar method in selinux and man listxattr.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>

netlabel: shorter names for the NetLabel catmap funcs/structs

Historically the NetLabel LSM secattr catmap functions and data
structures have had very long names which makes a mess of the NetLabel
code and anyone who uses NetLabel. This patch renames the catmap
functions and structures from "*_secattr_catmap_*" to just "*_catmap_*"
which improves things greatly.

There are no substantial code or logic changes in this patch.

Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Label cgroup files for systemd

The cgroup filesystem isn't ready for an LSM to
properly use extented attributes. This patch makes
files created in the cgroup filesystem usable by
a system running Smack and systemd.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Verify read access on file open - v3

Smack believes that many of the operatons that can
be performed on an open file descriptor are read operations.
The fstat and lseek system calls are examples.
An implication of this is that files shouldn't be open
if the task doesn't have read access even if it has
write access and the file is being opened write only.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: bidirectional UDS connect check

Smack IPC policy requires that the sender have write access
to the receiver. UDS streams don't do per-packet checks. The
only check is done at connect time. The existing code checks
if the connecting process can write to the other, but not the
other way around. This change adds a check that the other end
can write to the connecting process.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schuafler <casey@schaufler-ca.com>

Smack: Correctly remove SMACK64TRANSMUTE attribute

Sam Henderson points out that removing the SMACK64TRANSMUTE
attribute from a directory does not result in the directory
transmuting. This is because the inode flag indicating that
the directory is transmuting isn't cleared. The fix is a tad
less than trivial because smk_task and smk_mmap should have
been broken out, too.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

SMACK: Fix handling value==NULL in post setxattr

The function `smack_inode_post_setxattr` is called each
time that a setxattr is done, for any value of name.
The kernel allow to put value==NULL when size==0
to set an empty attribute value. The systematic
call to smk_import_entry was causing the dereference
of a NULL pointer hence a KERNEL PANIC!

The problem can be produced easily by issuing the
command `setfattr -n user.data file` under bash prompt
when SMACK is active.

Moving the call to smk_import_entry as proposed by this
patch is correcting the behaviour because the function
smack_inode_post_setxattr is called for the SMACK's
attributes only if the function smack_inode_setxattr validated
the value and its size (what will not be the case when size==0).

It also has a benefical effect to not fill the smack hash
with garbage values coming from any extended attribute
write.

Change-Id: Iaf0039c2be9bccb6cee11c24a3b44d209101fe47
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>

bugfix patch for SMACK

1. In order to remove any SMACK extended attribute from a file, a user
should have CAP_MAC_ADMIN capability. But user without having this
capability is able to remove SMACK64MMAP security attribute.

2. While validating size and value of smack extended attribute in
smack_inode_setsecurity hook, wrong error code is returned.

Signed-off-by: Pankaj Kumar <pamkaj.k2@samsung.com>
Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>

Smack: adds smackfs/ptrace interface

This allows to limit ptrace beyond the regular smack access rules.
It adds a smackfs/ptrace interface that allows smack to be configured
to require equal smack labels for PTRACE_MODE_ATTACH access.
See the changes in Documentation/security/Smack.txt below for details.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>

Smack: unify all ptrace accesses in the smack

The decision whether we can trace a process is made in the following
functions:
smack_ptrace_traceme()
smack_ptrace_access_check()
smack_bprm_set_creds() (in case the proces is traced)

This patch unifies all those decisions by introducing one function that
checks whether ptrace is allowed: smk_ptrace_rule_check().

This makes possible to actually trace with TRACEME where first the
TRACEME itself must be allowed and then exec() on a traced process.

Additional bugs fixed:
- The decision is made according to the mode parameter that is now correctly
translated from PTRACE_MODE_* to MAY_* instead of being treated 1:1.
PTRACE_MODE_READ requires MAY_READ.
PTRACE_MODE_ATTACH requires MAY_READWRITE.
- Add a smack audit log in case of exec() refused by bprm_set_creds().
- Honor the PTRACE_MODE_NOAUDIT flag and don't put smack audit info
in case this flag is set.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>

Smack: fix the subject/object order in smack_ptrace_traceme()

The order of subject/object is currently reversed in
smack_ptrace_traceme(). It is currently checked if the tracee has a
capability to trace tracer and according to this rule a decision is made
whether the tracer will be allowed to trace tracee.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>

Minor improvement of 'smack_sb_kern_mount'

Fix a possible memory access fault when transmute is true and isp is NULL.

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>

smack: fix key permission verification

For any keyring access type SMACK always used MAY_READWRITE access check.
It prevents reading the key with label "_", which should be allowed for anyone.

This patch changes default access check to MAY_READ and use MAY_READWRITE in only
appropriate cases.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

KEYS: Move the flags representing required permission to linux/key.h

Move the flags representing required permission to linux/key.h as the perm
parameter of security_key_permission() is in terms of them - and not the
permissions mask flags used in key->perm.

Whilst we're at it:

(1) Rename them to be KEY_NEED_xxx rather than KEY_xxx to avoid collisions
with symbols in uapi/linux/input.h.

(2) Don't use key_perm_t for a mask of required permissions, but rather limit
it to the permissions mask attached to the key and arguments related
directly to that.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>

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

Remove the call 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>

Smack: File receive audit correction

Eric Paris politely points out:

Inside smack_file_receive() it seems like you are initting the audit
field with LSM_AUDIT_DATA_TASK. And then use
smk_ad_setfield_u_fs_path().

Seems like LSM_AUDIT_DATA_PATH would make more sense. (and depending
on how it's used fix a crash...)

He is correct. This puts things in order.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Rationalize mount restrictions

The mount restrictions imposed by Smack rely heavily on the
use of the filesystem "floor", which is the label that all
processes writing to the filesystem must have access to. It
turns out that while the "floor" notion is sound, it has yet
to be fully implemented and has never been used.

The sb_mount and sb_umount hooks only make sense if the
filesystem floor is used actively, and it isn't. They can
be reintroduced if a rational restriction comes up. Until
then, they get removed.

The sb_kern_mount hook is required for the option processing.
It is too permissive in the case of unprivileged mounts,
effectively bypassing the CAP_MAC_ADMIN restrictions if
any of the smack options are specified. Unprivileged mounts
are no longer allowed to set Smack filesystem options.
Additionally, the root and default values are set to the
label of the caller, in keeping with the policy that objects
get the label of their creator.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Make the syslog control configurable

The syslog control requires that the calling proccess
have the floor ("_") Smack label. Tizen does not run any
processes except for kernel helpers with the floor label.
This changes allows the admin to configure a specific
label for syslog. The default value is the star ("*")
label, effectively removing the restriction. The value
can be set using smackfs/syslog for anyone who wants
a more restrictive behavior.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Prevent the * and @ labels from being used in SMACK64EXEC

Smack prohibits processes from using the star ("*") and web ("@") labels
because we don't want files with those labels getting created implicitly.
All setting of those labels should be done explicitly. The trouble is that
there is no check for these labels in the processing of SMACK64EXEC. That
is repaired.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Ptrace access check mode

When the ptrace security hooks were split the addition of
a mode parameter was not taken advantage of in the Smack
ptrace access check. This changes the access check from
always looking for read and write access to using the
passed mode. This will make use of /proc much happier.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Implement lock security mode

Linux file locking does not follow the same rules
as other mechanisms. Even though it is a write operation
a process can set a read lock on files which it has open
only for read access. Two programs with read access to
a file can use read locks to communicate.

This is not acceptable in a Mandatory Access Control
environment. Smack treats setting a read lock as the
write operation that it is. Unfortunately, many programs
assume that setting a read lock is a read operation.
These programs are unhappy in the Smack environment.

This patch introduces a new access mode (lock) to address
this problem. A process with lock access to a file can
set a read lock. A process with write access to a file can
set a read lock or a write lock. This prevents a situation
where processes are granted write access just so they can
set read locks.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: IPv6 casting error fix for 3.11

The original implementation of the Smack IPv6 port based
local controls works most of the time using a sockaddr as
a temporary variable, but not always as it overflows in
some circumstances. The correct data is a sockaddr_in6.
A struct sockaddr isn't as large as a struct sockaddr_in6.
There would need to be casting one way or the other. This
patch gets it the right way.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

Smack: network label match fix

The Smack code that matches incoming CIPSO tags with Smack labels
reaches through the NetLabel interfaces and compares the network
data with the CIPSO header associated with a Smack label. This was
done in a ill advised attempt to optimize performance. It works
so long as the categories fit in a single capset, but this isn't
always the case.

This patch changes the Smack code to use the appropriate NetLabel
interfaces to compare the incoming CIPSO header with the CIPSO
header associated with a label. It will always match the CIPSO
headers correctly.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security: smack: add a hash table to quicken smk_find_entry()

Accepted for the smack-next tree after changing the number of
slots from 128 to 16.

This patch adds a hash table to quicken searching of a smack label by its name.

Basically, the patch improves performance of SMACK initialization. Parsing of
rules involves translation from a string to a smack_known (aka label) entity
which is done in smk_find_entry().

The current implementation of the function iterates over a global list of
smack_known resulting in O(N) complexity for smk_find_entry(). The total
complexity of SMACK initialization becomes O(rules * labels). Therefore it
scales quadratically with a complexity of a system.

Applying the patch reduced the complexity of smk_find_entry() to O(1) as long
as number of label is in hundreds. If the number of labels is increased please
update SMACK_HASH_SLOTS constant defined in security/smack/smack.h. Introducing
the configuration of this constant with Kconfig or cmdline might be a good
idea.

The size of the hash table was adjusted experimentally. The rule set used by
TIZEN contains circa 17K rules for 500 labels. The table above contains
results of SMACK initialization using 'time smackctl apply' bash command.
The 'Ref' is a kernel without this patch applied. The consecutive values
refers to value of SMACK_HASH_SLOTS. Every measurement was repeated three
times to reduce noise.

| Ref | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512
--------------------------------------------------------------------------------------------
Run1 | 1.156 | 1.096 | 0.883 | 0.764 | 0.692 | 0.667 | 0.649 | 0.633 | 0.634 | 0.629 | 0.620
Run2 | 1.156 | 1.111 | 0.885 | 0.764 | 0.694 | 0.661 | 0.649 | 0.651 | 0.634 | 0.638 | 0.623
Run3 | 1.160 | 1.107 | 0.886 | 0.764 | 0.694 | 0.671 | 0.661 | 0.638 | 0.631 | 0.624 | 0.638
AVG | 1.157 | 1.105 | 0.885 | 0.764 | 0.693 | 0.666 | 0.653 | 0.641 | 0.633 | 0.630 | 0.627

Surprisingly, a single hlist is slightly faster than a double-linked list.
The speed-up saturates near 64 slots. Therefore I chose value 128 to provide
some margin if more labels were used.
It looks that IO becomes a new bottleneck.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>

xattr: Constify ->name member of "struct xattr".

Since everybody sets kstrdup()ed constant string to "struct xattr"->name but
nobody modifies "struct xattr"->name , we can omit kstrdup() and its failure
checking by constifying ->name member of "struct xattr".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Joel Becker <jlbec@evilplan.org> [ocfs2]
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Tested-by: Paul Moore <paul@paul-moore.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

Security: Add Hook to test if the particular xattr is part of a MAC model.

The interface to request security labels from user space is the xattr
interface. When requesting the security label from an NFS server it is
important to make sure the requested xattr actually is a MAC label. This allows
us to make sure that we get the desired semantics from the attribute instead of
something else such as capabilities or a time based LSM.

Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Smack: Add smkfstransmute mount option

Suppliment the smkfsroot mount option with another, smkfstransmute,
that does the same thing but also marks the root inode as
transmutting. This allows a freshly created filesystem to
be mounted with a transmutting heirarchy.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Improve access check performance

Each Smack label that the kernel has seen is added to a
list of labels. The list of access rules for a given subject
label hangs off of the label list entry for the label.
This patch changes the structures that contain subject
labels to point at the label list entry rather that the
label itself. Doing so removes a label list lookup in
smk_access() that was accounting for the largest single
chunk of Smack overhead.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Local IPv6 port based controls

Smack does not provide access controls on IPv6 communications.
This patch introduces a mechanism for maintaining Smack lables
for local IPv6 communications. It is based on labeling local ports.
The behavior should be compatible with any future "real" IPv6
support as it provides no interfaces for users to manipulate
the labeling. Remote IPv6 connections use the ambient label
the same way that unlabeled IPv4 packets are treated.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Fix NULL pointer dereference in smack_inode_unlink() and smack_inode_rmdir()

This patch fixes kernel Oops because of wrong common_audit_data type
in smack_inode_unlink() and smack_inode_rmdir().

When SMACK security module is enabled and SMACK logging is on (/smack/logging
is not zero) and you try to delete the file which
1) you cannot delete due to SMACK rules and logging of failures is on
or
2) you can delete and logging of success is on,

you will see following:

Unable to handle kernel NULL pointer dereference at virtual address 000002d7

[<...>] (strlen+0x0/0x28)
[<...>] (audit_log_untrustedstring+0x14/0x28)
[<...>] (common_lsm_audit+0x108/0x6ac)
[<...>] (smack_log+0xc4/0xe4)
[<...>] (smk_curacc+0x80/0x10c)
[<...>] (smack_inode_unlink+0x74/0x80)
[<...>] (security_inode_unlink+0x2c/0x30)
[<...>] (vfs_unlink+0x7c/0x100)
[<...>] (do_unlinkat+0x144/0x16c)

The function smack_inode_unlink() (and smack_inode_rmdir()) need
to log two structures of different types. First of all it does:

smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

This will set common audit data type to LSM_AUDIT_DATA_DENTRY
and store dentry for auditing (by function smk_curacc(), which in turn calls
dump_common_audit_data(), which is actually uses provided data and logs it).

/*
* You need write access to the thing you're unlinking
*/
rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
if (rc == 0) {
/*
* You also need write access to the containing directory
*/

Then this function wants to log anoter data:

smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
smk_ad_setfield_u_fs_inode(&ad, dir);

The function sets inode field, but don't change common_audit_data type.

rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
}

So the dump_common_audit() function incorrectly interprets inode structure
as dentry, and Oops will happen.

This patch reinitializes common_audit_data structures with correct type.
Also I removed unneeded
smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
initialization, because both dentry and inode pointers are stored
in the same union.

Signed-off-by: Igor Zhbanov <i.zhbanov@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

new helper: file_inode(file)

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

consitify do_mount() arguments

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

Smack: setprocattr memory leak fix

The data structure allocations being done in prepare_creds
are duplicated in smack_setprocattr. This results in the
structure allocated in prepare_creds being orphaned and
never freed. The duplicate code is removed from
smack_setprocattr.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: remove task_wait() hook.

On 12/20/2011 11:20 PM, Jarkko Sakkinen wrote:
> Allow SIGCHLD to be passed to child process without
> explicit policy. This will help to keep the access
> control policy simple and easily maintainable with
> complex applications that require use of multiple
> security contexts. It will also help to keep them
> as isolated as possible.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>

I have a slightly different version that applies to the
current smack-next tree.

Allow SIGCHLD to be passed to child process without
explicit policy. This will help to keep the access
control policy simple and easily maintainable with
complex applications that require use of multiple
security contexts. It will also help to keep them
as isolated as possible.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security/smack/smack_lsm.c | 37 ++++++++-----------------------------
1 files changed, 8 insertions(+), 29 deletions(-)

Smack: onlycap limits on CAP_MAC_ADMIN

Smack is integrated with the POSIX capabilities scheme,
using the capabilities CAP_MAC_OVERRIDE and CAP_MAC_ADMIN to
determine if a process is allowed to ignore Smack checks or
change Smack related data respectively. Smack provides an
additional restriction that if an onlycap value is set
by writing to /smack/onlycap only tasks with that Smack
label are allowed to use CAP_MAC_OVERRIDE.

This change adds CAP_MAC_ADMIN as a capability that is affected
by the onlycap mechanism.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: fix smack_new_inode bogosities

In January of 2012 Al Viro pointed out three bits of code that
he titled "new_inode_smack bogosities". This patch repairs these
errors.

1. smack_sb_kern_mount() included a NULL check that is impossible.
The check and NULL case are removed.
2. smack_kb_kern_mount() included pointless locking. The locking is
removed. Since this is the only place that lock was used the lock
is removed from the superblock_smack structure.
3. smk_fill_super() incorrectly and unnecessarily set the Smack label
for the smackfs root inode. The assignment has been removed.

Targeted for git://gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

split ->file_mmap() into ->mmap_addr()/->mmap_file()

... i.e. file-dependent and address-dependent checks.

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

split cap_mmap_addr() out of cap_file_mmap()

... switch callers.

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

Smack: allow for significantly longer Smack labels v4

V4 updated to current linux-security#next
Targeted for git://gitorious.org/smack-next/kernel.git

Modern application runtime environments like to use
naming schemes that are structured and generated without
human intervention. Even though the Smack limit of 23
characters for a label name is perfectly rational for
human use there have been complaints that the limit is
a problem in environments where names are composed from
a set or sources, including vendor, author, distribution
channel and application name. Names like

softwarehouse-pgwodehouse-coolappstore-mellowmuskrats

are becoming harder to avoid. This patch introduces long
label support in Smack. Labels are now limited to 255
characters instead of the old 23.

The primary reason for limiting the labels to 23 characters
was so they could be directly contained in CIPSO category sets.
This is still done were possible, but for labels that are too
large a mapping is required. This is perfectly safe for communication
that stays "on the box" and doesn't require much coordination
between boxes beyond what would have been required to keep label
names consistent.

The bulk of this patch is in smackfs, adding and updating
administrative interfaces. Because existing APIs can't be
changed new ones that do much the same things as old ones
have been introduced.

The Smack specific CIPSO data representation has been removed
and replaced with the data format used by netlabel. The CIPSO
header is now computed when a label is imported rather than
on use. This results in improved IP performance. The smack
label is now allocated separately from the containing structure,
allowing for larger strings.

Four new /smack interfaces have been introduced as four
of the old interfaces strictly required labels be specified
in fixed length arrays.

The access interface is supplemented with the check interface:
access "Subject Object rwxat"
access2 "Subject Object rwaxt"

The load interface is supplemented with the rules interface:
load "Subject Object rwxat"
load2 "Subject Object rwaxt"

The load-self interface is supplemented with the self-rules interface:
load-self "Subject Object rwxat"
load-self2 "Subject Object rwaxt"

The cipso interface is supplemented with the wire interface:
cipso "Subject lvl cnt c1 c2 ..."
cipso2 "Subject lvl cnt c1 c2 ..."

The old interfaces are maintained for compatibility.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

gfp flags for security_inode_alloc()?

Dave Chinner wrote:
> Yes, because you have no idea what the calling context is except
> for the fact that is from somewhere inside filesystem code and the
> filesystem could be holding locks. Therefore, GFP_NOFS is really the
> only really safe way to allocate memory here.

I see. Thank you.

I'm not sure, but can call trace happen where somewhere inside network
filesystem or stackable filesystem code with locks held invokes operations that
involves GFP_KENREL memory allocation outside that filesystem?
----------
[PATCH] SMACK: Fix incorrect GFP_KERNEL usage.

new_inode_smack() which can be called from smack_inode_alloc_security() needs
to use GFP_NOFS like SELinux's inode_alloc_security() does, for
security_inode_alloc() is called from inode_init_always() and
inode_init_always() is called from xfs_inode_alloc() which is using GFP_NOFS.

smack_inode_init_security() needs to use GFP_NOFS like
selinux_inode_init_security() does, for initxattrs() callback function (e.g.
btrfs_initxattrs()) which is called from security_inode_init_security() is
using GFP_NOFS.

smack_audit_rule_match() needs to use GFP_ATOMIC, for
security_audit_rule_match() can be called from audit_filter_user_rules() and
audit_filter_user_rules() is called from audit_filter_user() with RCU read lock
held.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>

Smack: recursive tramsmute

The transmuting directory feature of Smack requires that
the transmuting attribute be explicitly set in all cases.
It seems the users of this facility would expect that the
transmuting attribute be inherited by subdirectories that
are created in a transmuting directory. This does not seem
to add any additional complexity to the understanding of
how the system works.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: move label list initialization

A kernel with Smack enabled will fail if tmpfs has xattr support.

Move the initialization of predefined Smack label
list entries to the LSM initialization from the
smackfs setup. This became an issue when tmpfs
acquired xattr support, but was never correct.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

Smack: build when CONFIG_AUDIT not defined

This fixes builds where CONFIG_AUDIT is not defined and
CONFIG_SECURITY_SMACK=y.

This got introduced by the stack-usage reducation commit 48c62af68a40
("LSM: shrink the common_audit_data data union").

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SELinux: rename dentry_open to file_open

dentry_open takes a file, rename it to file_open

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

LSM: shrink the common_audit_data data union

After shrinking the common_audit_data stack usage for private LSM data I'm
not going to shrink the data union. To do this I'm going to move anything
larger than 2 void * ptrs to it's own structure and require it to be declared
separately on the calling stack. Thus hot paths which don't need more than
a couple pointer don't have to declare space to hold large unneeded
structures. I could get this down to one void * by dealing with the key
struct and the struct path. We'll see if that is helpful after taking care of
networking.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security: trim security.h

Trim security.h

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

vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb

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

Smack: compilation fix

On some build configurations PER_CLEAR_ON_SETID symbol was not
found when compiling smack_lsm.c. This patch fixes the issue by
explicitly doing #include <linux/personality.h>.

Signed-off-by: Jarkko Sakkinen <jarkko.j.sakkinen@gmail.com>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>

Smack: domain transition protections (v3)

Protections for domain transition:

- BPRM unsafe flags
- Secureexec
- Clear unsafe personality bits.
- Clear parent death signal

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>

Smack: Provide information for UDS getsockopt(SO_PEERCRED)

This patch is targeted for the smack-next tree.

This patch takes advantage of the recent changes for performance
and points the packet labels on UDS connect at the output label of
the far side. This makes getsockopt(...SO_PEERCRED...) function
properly. Without this change the getsockopt does not provide any
information.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Clean up comments

There are a number of comments in the Smack code that
are either malformed or include code. This patch cleans
them up.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Repair processing of fcntl

Al Viro pointed out that the processing of fcntl done
by Smack appeared poorly designed. He was right. There
are three things that required change. Most obviously,
the list of commands that really imply writing is limited
to those involving file locking and signal handling.
The initialization if the file security blob was
incomplete, requiring use of a heretofore unused LSM hook.
Finally, the audit information coming from a helper
masked the identity of the LSM hook. This patch corrects
all three of these defects.

This is targeted for the smack-next tree pending comments.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Smack: Rule list lookup performance

This patch is targeted for the smack-next tree.

Smack access checks suffer from two significant performance
issues. In cases where there are large numbers of rules the
search of the single list of rules is wasteful. Comparing the
string values of the smack labels is less efficient than a
numeric comparison would.

These changes take advantage of the Smack label list, which
maintains the mapping of Smack labels to secids and optional
CIPSO labels. Because the labels are kept perpetually, an
access check can be done strictly based on the address of the
label in the list without ever looking at the label itself.
Rather than keeping one global list of rules the rules with
a particular subject label can be based off of that label
list entry. The access check need never look at entries that
do not use the current subject label.

This requires that packets coming off the network with
CIPSO direct Smack labels that have never been seen before
be treated carefully. The only case where they could be
delivered is where the receiving socket has an IPIN star
label, so that case is explicitly addressed.

On a system with 39,800 rules (200 labels in all permutations)
a system with this patch runs an access speed test in 5% of
the time of the old version. That should be a best case
improvement. If all of the rules are associated with the
same subject label and all of the accesses are for processes
with that label (unlikely) the improvement is about 30%.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

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>

->permission() sanitizing: don't pass flags to ->inode_permission()

pass that via mask instead.

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

SMACK: smack_file_lock can use the struct path

smack_file_lock has a struct path, so use that instead of only the
dentry.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

LSM: separate LSM_AUDIT_DATA_DENTRY from LSM_AUDIT_DATA_PATH

This patch separates and audit message that only contains a dentry from
one that contains a full path. This allows us to make it harder to
misuse the interfaces or for the interfaces to be implemented wrong.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

LSM: split LSM_AUDIT_DATA_FS into _PATH and _INODE

The lsm common audit code has wacky contortions making sure which pieces
of information are set based on if it was given a path, dentry, or
inode. Split this into path and inode to get rid of some of the code
complexity.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>