audit: use KMEM_CACHE() instead of kmem_cache_create()

Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
[PM: subject line tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: Send netlink ACK before setting connection in auditd_set

When auditd_set sets the auditd_conn pointer, audit messages can
immediately be put on the socket by other kernel threads. If the backlog
is large or the rate is high, this can immediately fill the socket
buffer. If the audit daemon requested an ACK for this operation, a full
socket buffer causes the ACK to get dropped, also setting ENOBUFS on the
socket.

To avoid this race and ensure ACKs get through, fast-track the ACK in
this specific case to ensure it is sent before auditd_conn is set.

Signed-off-by: Chris Riches <chris.riches@nutanix.com>
[PM: fix some tab vs space damage]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: move trailing statements to next line

Fixes following checkpatch.pl issue:
ERROR: trailing statements should be on next line

Signed-off-by: Atul Kumar Pant <atulpant.linux@gmail.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: include security.h unconditionally

The ifdef-else logic is already in the header file, so include it
unconditionally, no functional changes here.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
[PM: fixed misspelling in the subject]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use time_after to compare time

Using time_{*} macro to compare time is better

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

audit: make is_audit_feature_set() static

Currently nobody use is_audit_feature_set() outside this file, so make
it static.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: remove redundant data_len check

data_len is already getting checked if it's less than 2 earlier in this
function.

Signed-off-by: Shreenidhi Shedi <sshedi@vmware.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: improve audit queue handling when "audit=1" on cmdline

When an admin enables audit at early boot via the "audit=1" kernel
command line the audit queue behavior is slightly different; the
audit subsystem goes to greater lengths to avoid dropping records,
which unfortunately can result in problems when the audit daemon is
forcibly stopped for an extended period of time.

This patch makes a number of changes designed to improve the audit
queuing behavior so that leaving the audit daemon in a stopped state
for an extended period does not cause a significant impact to the
system.

- kauditd_send_queue() is now limited to looping through the
passed queue only once per call. This not only prevents the
function from looping indefinitely when records are returned
to the current queue, it also allows any recovery handling in
kauditd_thread() to take place when kauditd_send_queue()
returns.

- Transient netlink send errors seen as -EAGAIN now cause the
record to be returned to the retry queue instead of going to
the hold queue. The intention of the hold queue is to store,
perhaps for an extended period of time, the events which led
up to the audit daemon going offline. The retry queue remains
a temporary queue intended to protect against transient issues
between the kernel and the audit daemon.

- The retry queue is now limited by the audit_backlog_limit
setting, the same as the other queues. This allows admins
to bound the size of all of the audit queues on the system.

- kauditd_rehold_skb() now returns records to the end of the
hold queue to ensure ordering is preserved in the face of
recent changes to kauditd_send_queue().

Cc: stable@vger.kernel.org
Fixes: 5b52330bbfe63 ("audit: fix auditd/kernel connection state tracking")
Fixes: f4b3ee3c85551 ("audit: improve robustness of the audit queue handling")
Reported-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Tested-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use struct_size() helper in audit_[send|make]_reply()

Make use of struct_size() helper instead of an open-coded calculation.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: ensure userspace is penalized the same as the kernel when under pressure

Due to the audit control mutex necessary for serializing audit
userspace messages we haven't been able to block/penalize userspace
processes that attempt to send audit records while the system is
under audit pressure. The result is that privileged userspace
applications have a priority boost with respect to audit as they are
not bound by the same audit queue throttling as the other tasks on
the system.

This patch attempts to restore some balance to the system when under
audit pressure by blocking these privileged userspace tasks after
they have finished their audit processing, and dropped the audit
control mutex, but before they return to userspace.

Reported-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Tested-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use struct_size() helper in kmalloc()

Make use of struct_size() helper instead of an open-coded calucation.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.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>

audit: improve robustness of the audit queue handling

If the audit daemon were ever to get stuck in a stopped state the
kernel's kauditd_thread() could get blocked attempting to send audit
records to the userspace audit daemon. With the kernel thread
blocked it is possible that the audit queue could grow unbounded as
certain audit record generating events must be exempt from the queue
limits else the system enter a deadlock state.

This patch resolves this problem by lowering the kernel thread's
socket sending timeout from MAX_SCHEDULE_TIMEOUT to HZ/10 and tweaks
the kauditd_send_queue() function to better manage the various audit
queues when connection problems occur between the kernel and the
audit daemon. With this patch, the backlog may temporarily grow
beyond the defined limits when the audit daemon is stopped and the
system is under heavy audit pressure, but kauditd_thread() will
continue to make progress and drain the queues as it would for other
connection problems. For example, with the audit daemon put into a
stopped state and the system configured to audit every syscall it
was still possible to shutdown the system without a kernel panic,
deadlock, etc.; granted, the system was slow to shutdown but that is
to be expected given the extreme pressure of recording every syscall.

The timeout value of HZ/10 was chosen primarily through
experimentation and this developer's "gut feeling". There is likely
no one perfect value, but as this scenario is limited in scope (root
privileges would be needed to send SIGSTOP to the audit daemon), it
is likely not worth exposing this as a tunable at present. This can
always be done at a later date if it proves necessary.

Cc: stable@vger.kernel.org
Fixes: 5b52330bbfe63 ("audit: fix auditd/kernel connection state tracking")
Reported-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Tested-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.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>

audit: Remove leftover reference to the audit_tasklet

This was replaced with a kauditd_wait kthread long ago,
back in:

b7d1125817c (AUDIT: Send netlink messages from a separate kernel thread)

Update the stale comment.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>

kernel/audit: convert comma to semicolon

Replace a comma between expression statements by a semicolon.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: replace atomic_add_return()

atomic_inc_return() is a little neater

Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: fix macros warnings

Some unused macros could cause gcc warning:
kernel/audit.c:68:0: warning: macro "AUDIT_UNINITIALIZED" is not used
[-Wunused-macros]
kernel/auditsc.c:104:0: warning: macro "AUDIT_AUX_IPCPERM" is not used
[-Wunused-macros]
kernel/auditsc.c:82:0: warning: macro "AUDITSC_INVALID" is not used
[-Wunused-macros]

AUDIT_UNINITIALIZED and AUDITSC_INVALID are still meaningful and should
be in incorporated.

Just remove AUDIT_AUX_IPCPERM.

Thanks comments from Richard Guy Briggs and Paul Moore.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: trigger accompanying records when no rules present

When there are no audit rules registered, mandatory records (config,
etc.) are missing their accompanying records (syscall, proctitle, etc.).

This is due to audit context dummy set on syscall entry based on absence
of rules that signals that no other records are to be printed. Clear the dummy
bit if any record is generated, open coding this in audit_log_start().

The proctitle context and dummy checks are pointless since the
proctitle record will not be printed if no syscall records are printed.

The fds array is reset to -1 after the first syscall to indicate it
isn't valid any more, but was never set to -1 when the context was
allocated to indicate it wasn't yet valid.

Check ctx->pwd in audit_log_name().

The audit_inode* functions can be called without going through
getname_flags() or getname_kernel() that sets audit_names and cwd, so
set the cwd in audit_alloc_name() if it has not already been done so due to
audit_names being valid and purge all other audit_getcwd() calls.

Revert the LSM dump_common_audit_data() LSM_AUDIT_DATA_* cases from the
ghak96 patch since they are no longer necessary due to cwd coverage in
audit_alloc_name().

Thanks to bauen1 <j2468h@googlemail.com> for reporting LSM situations in
which context->cwd is not valid, inadvertantly fixed by the ghak96 patch.

Please see upstream github issue
https://github.com/linux-audit/audit-kernel/issues/120
This is also related to upstream github issue
https://github.com/linux-audit/audit-kernel/issues/96

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

audit: fix a kernel-doc markup

typo:
kauditd_print_skb -> kauditd_printk_skb

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: Remove redundant null check

Because kfree_skb already checked NULL skb parameter,
so the additional check is unnecessary, just remove it.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: uninitialize variable audit_sig_sid

Checkpatch tool reports

"ERROR: do not initialise globals/statics to 0"

To fix this, audit_sig_sid is uninitialized
As this is stored in the .bss section,
the compiler can initialize the variable automatically.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: change unnecessary globals into statics

Variables sig_pid, audit_sig_uid and audit_sig_sid
are only used in the audit.c file across the kernel
Hence it appears no reason for declaring them as globals
This patch removes their global declarations from the .h file
and change them into static in the .c file.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

revert: 1320a4052ea1 ("audit: trigger accompanying records when no rules present")

Unfortunately the commit listed in the subject line above failed
to ensure that the task's audit_context was properly initialized/set
before enabling the "accompanying records". Depending on the
situation, the resulting audit_context could have invalid values in
some of it's fields which could cause a kernel panic/oops when the
task/syscall exists and the audit records are generated.

We will revisit the original patch, with the necessary fixes, in a
future kernel but right now we just want to fix the kernel panic
with the least amount of added risk.

Cc: stable@vger.kernel.org
Fixes: 1320a4052ea1 ("audit: trigger accompanying records when no rules present")
Reported-by: j2468h@googlemail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: report audit wait metric in audit status reply

In environments where the preservation of audit events and predictable
usage of system memory are prioritized, admins may use a combination of
--backlog_wait_time and -b options at the risk of degraded performance
resulting from backlog waiting. In some cases, this risk may be
preferred to lost events or unbounded memory usage. Ideally, this risk
can be mitigated by making adjustments when backlog waiting is detected.

However, detection can be difficult using the currently available
metrics. For example, an admin attempting to debug degraded performance
may falsely believe a full backlog indicates backlog waiting. It may
turn out the backlog frequently fills up but drains quickly.

To make it easier to reliably track degraded performance to backlog
waiting, this patch makes the following changes:

Add a new field backlog_wait_time_total to the audit status reply.
Initialize this field to zero. Add to this field the total time spent
by the current task on scheduled timeouts while the backlog limit is
exceeded. Reset field to zero upon request via AUDIT_SET.

Tested on Ubuntu 18.04 using complementary changes to the
audit-userspace and audit-testsuite:
- https://github.com/linux-audit/audit-userspace/pull/134
- https://github.com/linux-audit/audit-testsuite/pull/97

Signed-off-by: Max Englander <max.englander@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: purge audit_log_string from the intra-kernel audit API

audit_log_string() was inteded to be an internal audit function and
since there are only two internal uses, remove them. Purge all external
uses of it by restructuring code to use an existing audit_log_format()
or using audit_log_format().

Please see the upstream issue
https://github.com/linux-audit/audit-kernel/issues/84

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

treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

audit: log audit netlink multicast bind and unbind

Log information about programs connecting to and disconnecting from the
audit netlink multicast socket. This is needed so that during
investigations a security officer can tell who or what had access to the
audit trail. This helps to meet the FAU_SAR.2 requirement for Common
Criteria.

Here is the systemd startup event:
type=PROCTITLE msg=audit(2020-04-22 10:10:21.787:10) : proctitle=/init
type=SYSCALL msg=audit(2020-04-22 10:10:21.787:10) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x19 a1=0x555f4aac7e90 a2=0xc a3=0x7ffcb792ff44 items=0 ppid=0 pid=1 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=systemd exe=/usr/lib/systemd/systemd subj=kernel key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 10:10:21.787:10) : pid=1 uid=root auid=unset tty=(none) ses=unset subj=kernel comm=systemd exe=/usr/lib/systemd/systemd nl-mcgrp=1 op=connect res=yes

And events from the test suite that just uses close():
type=PROCTITLE msg=audit(2020-04-22 11:47:08.501:442) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SYSCALL msg=audit(2020-04-22 11:47:08.501:442) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x7 a1=0x563004378760 a2=0xc a3=0x0 items=0 ppid=815 pid=818 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 11:47:08.501:442) : pid=818 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=connect res=yes

type=UNKNOWN[1335] msg=audit(2020-04-22 11:47:08.501:443) : pid=818 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=disconnect res=yes

And the events from the test suite using setsockopt with NETLINK_DROP_MEMBERSHIP:
type=PROCTITLE msg=audit(2020-04-22 11:39:53.291:439) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SYSCALL msg=audit(2020-04-22 11:39:53.291:439) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x7 a1=0x5560877c2d20 a2=0xc a3=0x0 items=0 ppid=772 pid=775 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 11:39:53.291:439) : pid=775 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=connect res=yes

type=PROCTITLE msg=audit(2020-04-22 11:39:53.292:440) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SYSCALL msg=audit(2020-04-22 11:39:53.292:440) : arch=x86_64 syscall=setsockopt success=yes exit=0 a0=0x7 a1=SOL_NETLINK a2=0x2 a3=0x7ffc8366f000 items=0 ppid=772 pid=775 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-04-22 11:39:53.292:440) : pid=775 uid=root auid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=disconnect res=yes

Please see the upstream issue tracker at
https://github.com/linux-audit/audit-kernel/issues/28
With the feature description at
https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Multicast-Socket-Join-Part
The testsuite support is at
https://github.com/rgbriggs/audit-testsuite/compare/ghak28-mcast-part-join
https://github.com/linux-audit/audit-testsuite/pull/93
And the userspace support patch is at
https://github.com/linux-audit/audit-userspace/pull/114

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

audit: fix a net reference leak in audit_list_rules_send()

If audit_list_rules_send() fails when trying to create a new thread
to send the rules it also fails to cleanup properly, leaking a
reference to a net structure. This patch fixes the error patch and
renames audit_send_list() to audit_send_list_thread() to better
match its cousin, audit_send_reply_thread().

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

audit: fix a net reference leak in audit_send_reply()

If audit_send_reply() fails when trying to create a new thread to
send the reply it also fails to cleanup properly, leaking a reference
to a net structure. This patch fixes the error path and makes a
handful of other cleanups that came up while fixing the code.

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

audit: check the length of userspace generated audit records

Commit 756125289285 ("audit: always check the netlink payload length
in audit_receive_msg()") fixed a number of missing message length
checks, but forgot to check the length of userspace generated audit
records. The good news is that you need CAP_AUDIT_WRITE to submit
userspace audit records, which is generally only given to trusted
processes, so the impact should be limited.

Cc: stable@vger.kernel.org
Fixes: 756125289285 ("audit: always check the netlink payload length in audit_receive_msg()")
Reported-by: syzbot+49e69b4d71a420ceda3e@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: trigger accompanying records when no rules present

When there are no audit rules registered, mandatory records (config,
etc.) are missing their accompanying records (syscall, proctitle, etc.).

This is due to audit context dummy set on syscall entry based on absence
of rules that signals that no other records are to be printed.

Clear the dummy bit if any record is generated.

The proctitle context and dummy checks are pointless since the
proctitle record will not be printed if no syscall records are printed.

Please see upstream github issue
https://github.com/linux-audit/audit-kernel/issues/120

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

audit: always check the netlink payload length in audit_receive_msg()

This patch ensures that we always check the netlink payload length
in audit_receive_msg() before we take any action on the payload
itself.

Cc: stable@vger.kernel.org
Reported-by: syzbot+399c44bf1f43b8747403@syzkaller.appspotmail.com
Reported-by: syzbot+e4b12d8d202701f08b6d@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: Add __rcu annotation to RCU pointer

Add __rcu annotation to RCU-protected global pointer auditd_conn.

auditd_conn is an RCU-protected global pointer,i.e., accessed
via RCU methods rcu_dereference() and rcu_assign_pointer(),
hence it must be annotated with __rcu for sparse to report
warnings/errors correctly.

Fix multiple instances of the sparse error:
error: incompatible types in comparison expression
(different address spaces)

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
[PM: tweak subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: remove redundant condition check in kauditd_thread()

Warning is found by the code analysis tool:
"the condition 'if(ac && rc < 0)' is redundant: ac"

The @ac variable has been checked before. It can't be a null pointer
here, so remove the redundant condition check.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: Report suspicious O_CREAT usage

This renames the very specific audit_log_link_denied() to
audit_log_path_denied() and adds the AUDIT_* type as an argument. This
allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
report the fifo/regular file creation restrictions that were introduced
in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
regular files").

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

audit: deliver signal_info regarless of syscall

When a process signals the audit daemon (shutdown, rotate, resume,
reconfig) but syscall auditing is not enabled, we still want to know the
identity of the process sending the signal to the audit daemon.

Move audit_signal_info() out of syscall auditing to general auditing but
create a new function audit_signal_info_syscall() to take care of the
syscall dependent parts for when syscall auditing is enabled.

Please see the github kernel audit issue
https://github.com/linux-audit/audit-kernel/issues/111

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

audit: connect LOGIN record to its syscall record

Currently the AUDIT_LOGIN event is a standalone record that isn't
connected to any other records that may be part of its syscall event. To
avoid the confusion of generating two events, connect the records by
using its syscall context.

Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/110

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

audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL

Remove audit_context from struct task_struct and struct audit_buffer
when CONFIG_AUDIT is enabled but CONFIG_AUDITSYSCALL is not.

Also, audit_log_name() (and supporting inode and fcaps functions) should
have been put back in auditsc.c when soft and hard link logging was
normalized since it is only used by syscall auditing.

See github issue https://github.com/linux-audit/audit-kernel/issues/105

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

audit: ignore fcaps on umount

Don't fetch fcaps when umount2 is called to avoid a process hang while
it waits for the missing resource to (possibly never) re-appear.

Note the comment above user_path_mountpoint_at():
* A umount is a special case for path walking. We're not actually interested
* in the inode in this situation, and ESTALE errors can be a problem. We
* simply want track down the dentry and vfsmount attached at the mountpoint
* and avoid revalidating the last component.

This can happen on ceph, cifs, 9p, lustre, fuse (gluster) or NFS.

Please see the github issue tracker
https://github.com/linux-audit/audit-kernel/issues/100

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in audit_log_fcaps()]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: add support for fcaps v3

V3 namespaced file capabilities were introduced in
commit 8db6c34f1dbc ("Introduce v3 namespaced file capabilities")

Add support for these by adding the "frootid" field to the existing
fcaps fields in the NAME and BPRM_FCAPS records.

Please see github issue
https://github.com/linux-audit/audit-kernel/issues/103

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
[PM: comment tweak to fit an 80 char line width]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: move loginuid and sessionid from CONFIG_AUDITSYSCALL to CONFIG_AUDIT

loginuid and sessionid (and audit_log_session_info) should be part of
CONFIG_AUDIT scope and not CONFIG_AUDITSYSCALL since it is used in
CONFIG_CHANGE, ANOM_LINK, FEATURE_CHANGE (and INTEGRITY_RULE), none of
which are otherwise dependent on AUDITSYSCALL.

Please see github issue
https://github.com/linux-audit/audit-kernel/issues/104

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: tweaked subject line for better grep'ing]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: add syscall information to CONFIG_CHANGE records

Tie syscall information to all CONFIG_CHANGE calls since they are all a
result of user actions.

Exclude user records from syscall context:
Since the function audit_log_common_recv_msg() is shared by a number of
AUDIT_CONFIG_CHANGE and the entire range of AUDIT_USER_* record types,
and since the AUDIT_CONFIG_CHANGE message type has been converted to a
syscall accompanied record type, special-case the AUDIT_USER_* range of
messages so they remain standalone records.

See: https://github.com/linux-audit/audit-kernel/issues/59
See: https://github.com/linux-audit/audit-kernel/issues/50

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fix line lengths in kernel/audit.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: give a clue what CONFIG_CHANGE op was involved

The failure to add an audit rule due to audit locked gives no clue
what CONFIG_CHANGE operation failed.
Similarly the set operation is the only other operation that doesn't
give the "op=" field to indicate the action.
All other CONFIG_CHANGE records include an op= field to give a clue as
to what sort of configuration change is being executed.

Since these are the only CONFIG_CHANGE records that that do not have an
op= field, add them to bring them in line with the rest.

Old records:
type=CONFIG_CHANGE msg=audit(1519812997.781:374): pid=610 uid=0 auid=0 ses=1 subj=... audit_enabled=2 res=0
type=CONFIG_CHANGE msg=audit(2018-06-14 14:55:04.507:47) : audit_enabled=1 old=1 auid=unset ses=unset subj=... res=yes

New records:
type=CONFIG_CHANGE msg=audit(1520958477.855:100): pid=610 uid=0 auid=0 ses=1 subj=... op=add_rule audit_enabled=2 res=0

type=CONFIG_CHANGE msg=audit(2018-06-14 14:55:04.507:47) : op=set audit_enabled=1 old=1 auid=unset ses=unset subj=... res=yes

See: https://github.com/linux-audit/audit-kernel/issues/59

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed checkpatch.pl line length problems]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: remove duplicated include from audit.c

Remove duplicated include.

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

audit: shorten PATH cap values when zero

Since the vast majority of files (99.993% on a typical system) have no
fcaps, display "0" instead of the full zero-padded 16 hex digits in the
two PATH record cap_f* fields to save netlink bandwidth and disk space.

Simply changing the format to %x won't work since the value is two (or
possibly more in the future) 32-bit hexadecimal values concatenated and
bits in higher order values will be misrepresented.

Passes audit-testsuite and userspace tools already work fine.
Please see the github issue tracker for more details
https://github.com/linux-audit/audit-kernel/issues/101

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

audit: use current whenever possible

There are many places, notably audit_log_task_info() and
audit_log_exit(), that take task_struct pointers but in reality they
are always working on the current task. This patch eliminates the
task_struct arguments and uses current directly which allows a number
of cleanups as well.

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

audit: minimize our use of audit_log_format()

There are some cases where we are making multiple audit_log_format()
calls in a row, for no apparent reason. Squash these down to a
single audit_log_format() call whenever possible.

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

audit: use session_info helper

There are still a couple of places (mark and watch config changes) that
open code auid and ses fields in sequence in records instead of using
the audit_log_session_info() helper. Use the helper. Adjust the helper
to accommodate being the first fields. Passes audit-testsuite.

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

audit: use ktime_get_coarse_real_ts64() for timestamps

Commit c72051d5778a ("audit: use ktime_get_coarse_ts64() for time
access") converted audit's use of current_kernel_time64() to the
new ktime_get_coarse_ts64() function. Unfortunately this resulted
in incorrect timestamps, e.g. events stamped with the year 1969
despite it being 2018. This patch corrects this by using
ktime_get_coarse_real_ts64() just like the current_kernel_time64()
wrapper.

Fixes: c72051d5778a ("audit: use ktime_get_coarse_ts64() for time access")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use ktime_get_coarse_ts64() for time access

The API got renamed for consistency with the other time accessors,
this changes the audit caller as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: eliminate audit_enabled magic number comparison

Remove comparison of audit_enabled to magic numbers outside of audit.

Related: https://github.com/linux-audit/audit-kernel/issues/86

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

audit: rename FILTER_TYPE to FILTER_EXCLUDE

The AUDIT_FILTER_TYPE name is vague and misleading due to not describing
where or when the filter is applied and obsolete due to its available
filter fields having been expanded.

Userspace has already renamed it from AUDIT_FILTER_TYPE to
AUDIT_FILTER_EXCLUDE without checking if it already exists. The
userspace maintainer assures that as long as it is set to the same value
it will not be a problem since the userspace code does not treat
compiler warnings as errors. If this policy changes then checks if it
already exists can be added at the same time.

See: https://github.com/linux-audit/audit-kernel/issues/89

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

audit: use inline function to get audit context

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

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

audit: add syscall information to FEATURE_CHANGE records

Tie syscall information to FEATURE_CHANGE calls since it is a result of
user action.

See: https://github.com/linux-audit/audit-kernel/issues/80

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: 80-char fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

net: Drop pernet_operations::async

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Align function definition open/close braces

Some functions definitions have either the initial open brace and/or
the closing brace outside of column 1.

Move those braces to column 1.

This allows various function analyzers like gnu complexity to work
properly for these modified functions.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

audit: remove path param from link denied function

In commit 45b578fe4c3cade6f4ca1fc934ce199afd857edc
("audit: link denied should not directly generate PATH record")
the need for the struct path *link parameter was removed.
Remove the now useless struct path argument.

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

audit: link denied should not directly generate PATH record

Audit link denied events generate duplicate PATH records which disagree
in different ways from symlink and hardlink denials.
audit_log_link_denied() should not directly generate PATH records.

See: https://github.com/linux-audit/audit-kernel/issues/21

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

audit: make ANOM_LINK obey audit_enabled and audit_dummy_context

Audit link denied events emit disjointed records when audit is disabled.
No records should be emitted when audit is disabled.

See: https://github.com/linux-audit/audit-kernel/issues/21

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

audit: do not panic on invalid boot parameter

If you pass in an invalid audit boot parameter value, e.g. "audit=off",
the kernel panics very early in boot before the regular console is
initialized. Unless you have earlyprintk enabled, there is no
indication of what the problem is on the console.

Convert the panic() calls to pr_err(), and leave auditing enabled if an
invalid parameter value was passed in.

Modify the parameter to also accept "on" or "off" as valid values, and
update the documentation accordingly.

Signed-off-by: Greg Edwards <gedwards@ddn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: track the owner of the command mutex ourselves

Evidently the __mutex_owner() function was never intended for use
outside the core mutex code, so build a thing locking wrapper around
the mutex code which allows us to track the mutex owner.

One, arguably positive, side effect is that this allows us to hide
the audit_cmd_mutex inside of kernel/audit.c behind the lock/unlock
functions.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: return on memory error to avoid null pointer dereference

If there is a memory allocation error when trying to change an audit
kernel feature value, the ignored allocation error will trigger a NULL
pointer dereference oops on subsequent use of that pointer. Return
instead.

Passes audit-testsuite.
See: https://github.com/linux-audit/audit-kernel/issues/76

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: not necessary (other funcs check for NULL), but a good practice]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: update bugtracker and source URIs

Since the Linux Audit project has transitioned completely over to
github, update the MAINTAINERS file and the primary audit source file to
reflect that reality.

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

net: Convert audit_net_ops

This patch starts to convert pernet_subsys, registered
from postcore initcalls.

audit_net_init() creates netlink socket, while audit_net_exit()
destroys it. The rest of the pernet_list are not interested
in the socket, so we make audit_net_ops async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Audit: remove unused audit_log_secctx function

The function audit_log_secctx() is unused in the upstream kernel.
All it does is wrap another function that doesn't need wrapping.
It claims to give you the SELinux context, but that is not true if
you are using a different security module.

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

audit: Allow auditd to set pid to 0 to end auditing

The API to end auditing has historically been for auditd to set the
pid to 0. This patch restores that functionality.

See: https://github.com/linux-audit/audit-kernel/issues/69

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

audit: use audit_set_enabled() in audit_enable()

Use audit_set_enabled() to enable auditing during early boot. This
obviously won't emit an audit change record, but it will work anyway
and should help prevent in future problems by consolidating the
enable/disable code in one function.

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

audit: convert audit_ever_enabled to a boolean

We were treating it as a boolean, let's make it a boolean to help
avoid future mistakes.

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

audit: don't use simple_strtol() anymore

The simple_strtol() function is deprecated, use kstrtol() instead.

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

audit: initialize the audit subsystem as early as possible

We can't initialize the audit subsystem until after the network layer
is initialized (core_initcall), but do it soon after.

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

audit: ensure that 'audit=1' actually enables audit for PID 1

Prior to this patch we enabled audit in audit_init(), which is too
late for PID 1 as the standard initcalls are run after the PID 1 task
is forked. This means that we never allocate an audit_context (see
audit_alloc()) for PID 1 and therefore miss a lot of audit events
generated by PID 1.

This patch enables audit as early as possible to help ensure that when
PID 1 is forked it can allocate an audit_context if required.

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

audit: update the function comments

Update the function comments to match the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: Reduce overhead using a coarse clock

Commit 2115bb250f26 ("audit: Use timespec64 to represent audit timestamps")
noted that audit timestamps were not y2038 safe and used a 64-bit
timestamp. In itself, this makes sense but the conversion was from
CURRENT_TIME to ktime_get_real_ts64() which is a heavier call to record
an accurate timestamp which is required in some, but not all, cases. The
impact is that when auditd is running without any rules that all syscalls
have higher overhead. This is visible in the sysbench-thread benchmark as
a 11.5% performance hit. That benchmark is dumb as rocks but it's also
visible in redis as an 8-10% hit on all operations which is of greater
concern. It is somewhat stupid of audit to track syscalls without any
rules related to syscalls but that is how it behaves.

The overhead can be directly measured with perf comparing 4.9 with 4.12

4.9
7.76% sysbench [kernel.vmlinux] [k] __schedule
7.62% sysbench [kernel.vmlinux] [k] _raw_spin_lock
7.37% sysbench libpthread-2.22.so [.] __lll_lock_elision
7.29% sysbench [kernel.vmlinux] [.] syscall_return_via_sysret
6.59% sysbench [kernel.vmlinux] [k] native_sched_clock
5.21% sysbench libc-2.22.so [.] __sched_yield
4.38% sysbench [kernel.vmlinux] [k] entry_SYSCALL_64
4.28% sysbench [kernel.vmlinux] [k] do_syscall_64
3.49% sysbench libpthread-2.22.so [.] __lll_unlock_elision
3.13% sysbench [kernel.vmlinux] [k] __audit_syscall_exit
2.87% sysbench [kernel.vmlinux] [k] update_curr
2.73% sysbench [kernel.vmlinux] [k] pick_next_task_fair
2.31% sysbench [kernel.vmlinux] [k] syscall_trace_enter
2.20% sysbench [kernel.vmlinux] [k] __audit_syscall_entry
.....
0.00% swapper [kernel.vmlinux] [k] read_tsc

4.12
7.84% sysbench [kernel.vmlinux] [k] __schedule
7.05% sysbench [kernel.vmlinux] [k] _raw_spin_lock
6.57% sysbench libpthread-2.22.so [.] __lll_lock_elision
6.50% sysbench [kernel.vmlinux] [.] syscall_return_via_sysret
5.95% sysbench [kernel.vmlinux] [k] read_tsc
5.71% sysbench [kernel.vmlinux] [k] native_sched_clock
4.78% sysbench libc-2.22.so [.] __sched_yield
4.30% sysbench [kernel.vmlinux] [k] entry_SYSCALL_64
3.94% sysbench [kernel.vmlinux] [k] do_syscall_64
3.37% sysbench libpthread-2.22.so [.] __lll_unlock_elision
3.32% sysbench [kernel.vmlinux] [k] __audit_syscall_exit
2.91% sysbench [kernel.vmlinux] [k] __getnstimeofday64

Note the additional overhead from read_tsc which goes from 0% to 5.95%.
This is on a single-socket E3-1230 but similar overheads have been measured
on an older machine which the patch also eliminates.

The patch in question has no explanation as to why a fully-accurate timestamp
is required and is likely an oversight. Using a coarser, but monotically
increasing, timestamp the overhead can be eliminated. While it can be
worked around by configuring or disabling audit, it's tricky enough to
detect that a kernel fix is justified. With this patch, we see the following;

sysbenchthread
4.9.0 4.12.0 4.12.0
vanilla vanilla coarse-v1r1
Amean 1 1.49 ( 0.00%) 1.66 ( -11.42%) 1.51 ( -1.34%)
Amean 3 1.48 ( 0.00%) 1.65 ( -11.45%) 1.50 ( -0.96%)
Amean 5 1.49 ( 0.00%) 1.67 ( -12.31%) 1.51 ( -1.83%)
Amean 7 1.49 ( 0.00%) 1.66 ( -11.72%) 1.50 ( -0.67%)
Amean 12 1.48 ( 0.00%) 1.65 ( -11.57%) 1.52 ( -2.89%)
Amean 16 1.49 ( 0.00%) 1.65 ( -11.13%) 1.51 ( -1.73%)

The benchmark is reporting the time required for different thread counts to
lock/unlock a private mutex which, while dense, demonstrates the syscall
overhead. This is showing that 4.12 took a 11-12% hit but the overhead is
almost eliminated by the patch. While the variance is not reported here,
it's well within the noise with the patch applied.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: fix memleak in auditd_send_unicast_skb.

Found this issue by kmemleak report, auditd_send_unicast_skb
did not free skb if rcu_dereference(auditd_conn) returns null.

unreferenced object 0xffff88082568ce00 (size 256):
comm "auditd", pid 1119, jiffies 4294708499
backtrace:
[<ffffffff8176166a>] kmemleak_alloc+0x4a/0xa0
[<ffffffff8121820c>] kmem_cache_alloc_node+0xcc/0x210
[<ffffffff8161b99d>] __alloc_skb+0x5d/0x290
[<ffffffff8113c614>] audit_make_reply+0x54/0xd0
[<ffffffff8113dfa7>] audit_receive_msg+0x967/0xd70
----------------
(gdb) list *audit_receive_msg+0x967
0xffffffff8113dff7 is in audit_receive_msg (kernel/audit.c:1133).
1132 skb = audit_make_reply(0, AUDIT_REPLACE, 0,
0, &pvnr, sizeof(pvnr));
---------------
[<ffffffff8113e402>] audit_receive+0x52/0xa0
[<ffffffff8166c561>] netlink_unicast+0x181/0x240
[<ffffffff8166c8e2>] netlink_sendmsg+0x2c2/0x3b0
[<ffffffff816112e8>] sock_sendmsg+0x38/0x50
[<ffffffff816117a2>] SYSC_sendto+0x102/0x190
[<ffffffff81612f4e>] SyS_sendto+0xe/0x10
[<ffffffff8176d337>] entry_SYSCALL_64_fastpath+0x1a/0xa5
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Shu Wang <shuwang@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: make sure we never skip the multicast broadcast

When the auditd connection is reset, either intentionally or due to
a failure, any records that were in the main backlog queue would not
be sent in a multicast broadcast. This patch fixes this problem by
not flushing the main backlog queue on a connection reset, the main
kauditd_thread() will take care of that normally.

Resolves: https://github.com/linux-audit/audit-kernel/issues/41
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: fix a race condition with the auditd tracking code

Originally reported by Adam and Dusty, it appears we have a small
race window in kauditd_thread(), as documented in the Fedora BZ:

* https://bugzilla.redhat.com/show_bug.cgi?id=1459326#c35

"This issue is partly due to the read-copy nature of RCU, and
partly due to how we sync the auditd_connection state across
kauditd_thread and the audit control channel. The kauditd_thread
thread is always running so it can service the record queues and
emit the multicast messages, if it happens to be just past the
"main_queue" label, but before the "if (sk == NULL || ...)"
if-statement which calls auditd_reset() when the new auditd
connection is registered it could end up resetting the auditd
connection, regardless of if it is valid or not. This is a rather
small window and the variable nature of multi-core scheduling
explains why this is proving rather difficult to reproduce."

The fix is to have functions only call auditd_reset() when they
believe that the kernel/auditd connection is still valid, e.g.
non-NULL, and to have these callers pass their local copy of the
auditd_connection pointer to auditd_reset() where it can be compared
with the current connection state before resetting. If the caller
has a stale state tracking pointer then the reset is ignored.

We also make a small change to kauditd_thread() so that if the
kernel/auditd connection is dead we skip the retry queue and send the
records straight to the hold queue. This is necessary as we used to
rely on auditd_reset() to occasionally purge the retry queue but we
are going to be calling the reset function much less now and we want
to make sure the retry queue doesn't grow unbounded.

Reported-by: Adam Williamson <awilliam@redhat.com>
Reported-by: Dusty Mabe <dustymabe@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: unswing cap_* fields in PATH records

The cap_* fields swing in and out of PATH records.
If no capabilities are set, the cap_* fields are completely missing and when
one of the cap_fi or cap_fp values is empty, that field is omitted.

Original:
type=PATH msg=audit(04/20/2017 12:17:11.222:193) : item=1 name=/lib64/ld-linux-x86-64.so.2 inode=787694 dev=08:03 mode=file,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:ld_so_t:s0 nametype=NORMAL
type=PATH msg=audit(04/20/2017 12:17:11.222:193) : item=0 name=/home/sleep inode=1319469 dev=08:03 mode=file,suid,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:bin_t:s0 nametype=NORMAL cap_fp=sys_admin cap_fe=1 cap_fver=2

Normalize the PATH record by always printing all 4 cap_* fields.

Fixed:
type=PATH msg=audit(04/20/2017 13:01:31.679:201) : item=1 name=/lib64/ld-linux-x86-64.so.2 inode=787694 dev=08:03 mode=file,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:ld_so_t:s0 nametype=NORMAL cap_fp=none cap_fi=none cap_fe=0 cap_fver=0
type=PATH msg=audit(04/20/2017 13:01:31.679:201) : item=0 name=/home/sleep inode=1319469 dev=08:03 mode=file,suid,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:bin_t:s0 nametype=NORMAL cap_fp=sys_admin cap_fi=none cap_fe=1 cap_fver=2

See: https://github.com/linux-audit/audit-kernel/issues/42

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

audit: fix the RCU locking for the auditd_connection structure

Cong Wang correctly pointed out that the RCU read locking of the
auditd_connection struct was wrong, this patch correct this by
adopting a more traditional, and correct RCU locking model.

This patch is heavily based on an earlier prototype by Cong Wang.

Cc: <stable@vger.kernel.org> # 4.11.x-
Reported-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use kmem_cache to manage the audit_buffer cache

The audit subsystem implemented its own buffer cache mechanism which
is a bit silly these days when we could use the kmem_cache construct.

Some credit is due to Florian Westphal for originally proposing that
we remove the audit cache implementation in favor of simple
kmalloc()/kfree() calls, but I would rather have a dedicated slab
cache to ease debugging and future stats/performance work.

Cc: Florian Westphal <fw@strlen.de>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: Use timespec64 to represent audit timestamps

struct timespec is not y2038 safe.
Audit timestamps are recorded in string format into
an audit buffer for a given context.
These mark the entry timestamps for the syscalls.
Use y2038 safe struct timespec64 to represent the times.
The log strings can handle this transition as strings can
hold upto 1024 characters.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: store the auditd PID as a pid struct instead of pid_t

This is arguably the right thing to do, and will make it easier when
we start supporting multiple audit daemons in different namespaces.

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

audit: kernel generated netlink traffic should have a portid of 0

We were setting the portid incorrectly in the netlink message headers,
fix that to always be 0 (nlmsg_pid = 0).

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

audit: combine audit_receive() and audit_receive_skb()

There is no reason to have both of these functions, combine the two.

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

netlink: extended ACK reporting

Add the base infrastructure and UAPI for netlink extended ACK
reporting. All "manual" calls to netlink_ack() pass NULL for now and
thus don't get extended ACK reporting.

Big thanks goes to Pablo Neira Ayuso for not only bringing up the
whole topic at netconf (again) but also coming up with the nlattr
passing trick and various other ideas.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: make sure we don't let the retry queue grow without bounds

The retry queue is intended to provide a temporary buffer in the case
of transient errors when communicating with auditd, it is not meant
as a long life queue, that functionality is provided by the hold
queue.

This patch fixes a problem identified by Seth where the retry queue
could grow uncontrollably if an auditd instance did not connect to
the kernel to drain the queues. This commit fixes this by doing the
following:

* Make sure we always call auditd_reset() if we decide the connection
with audit is really dead. There were some cases in
kauditd_hold_skb() where we did not reset the connection, this patch
relocates the reset calls to kauditd_thread() so all the error
conditions are caught and the connection reset. As a side effect,
this means we could move auditd_reset() and get rid of the forward
definition at the top of kernel/audit.c.

* We never checked the status of the auditd connection when
processing the main audit queue which meant that the retry queue
could grow unchecked. This patch adds a call to auditd_reset()
after the main queue has been processed if auditd is not connected,
the auditd_reset() call will make sure the retry and hold queues are
correctly managed/flushed so that the retry queue remains reasonable.

Cc: <stable@vger.kernel.org> # 4.10.x-: 5b52330bbfe6
Reported-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: fix auditd/kernel connection state tracking

What started as a rather straightforward race condition reported by
Dmitry using the syzkaller fuzzer ended up revealing some major
problems with how the audit subsystem managed its netlink sockets and
its connection with the userspace audit daemon. Fixing this properly
had quite the cascading effect and what we are left with is this rather
large and complicated patch. My initial goal was to try and decompose
this patch into multiple smaller patches, but the way these changes
are intertwined makes it difficult to split these changes into
meaningful pieces that don't break or somehow make things worse for
the intermediate states.

The patch makes a number of changes, but the most significant are
highlighted below:

* The auditd tracking variables, e.g. audit_sock, are now gone and
replaced by a RCU/spin_lock protected variable auditd_conn which is
a structure containing all of the auditd tracking information.

* We no longer track the auditd sock directly, instead we track it
via the network namespace in which it resides and we use the audit
socket associated with that namespace. In spirit, this is what the
code was trying to do prior to this patch (at least I think that is
what the original authors intended), but it was done rather poorly
and added a layer of obfuscation that only masked the underlying
problems.

* Big backlog queue cleanup, again. In v4.10 we made some pretty big
changes to how the audit backlog queues work, here we haven't changed
the queue design so much as cleaned up the implementation. Brought
about by the locking changes, we've simplified kauditd_thread() quite
a bit by consolidating the queue handling into a new helper function,
kauditd_send_queue(), which allows us to eliminate a lot of very
similar code and makes the looping logic in kauditd_thread() clearer.

* All netlink messages sent to auditd are now sent via
auditd_send_unicast_skb(). Other than just making sense, this makes
the lock handling easier.

* Change the audit_log_start() sleep behavior so that we never sleep
on auditd events (unchanged) or if the caller is holding the
audit_cmd_mutex (changed). Previously we didn't sleep if the caller
was auditd or if the message type fell between a certain range; the
type check was a poor effort of doing what the cmd_mutex check now
does. Richard Guy Briggs originally proposed not sleeping the
cmd_mutex owner several years ago but his patch wasn't acceptable
at the time. At least the idea lives on here.

* A problem with the lost record counter has been resolved. Steve
Grubb and I both happened to notice this problem and according to
some quick testing by Steve, this problem goes back quite some time.
It's largely a harmless problem, although it may have left some
careful sysadmins quite puzzled.

Cc: <stable@vger.kernel.org> # 4.10.x-
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: add feature audit_lost reset

Add a method to reset the audit_lost value.

An AUDIT_SET message with the AUDIT_STATUS_LOST flag set by itself
will return a positive value repesenting the current audit_lost value
and reset the counter to zero. If AUDIT_STATUS_LOST is not the
only flag set, the reset command will be ignored. The value sent with
the command is ignored. The return value will be the +ve lost value at
reset time.

An AUDIT_CONFIG_CHANGE message will be queued to the listening audit
daemon. The message will be a standard CONFIG_CHANGE message with the
fields "lost=0" and "old=" with the latter containing the value of
audit_lost at reset time.

See: https://github.com/linux-audit/audit-kernel/issues/3

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

audit: Make AUDIT_KERNEL event conform to the specification

The AUDIT_KERNEL event is not following name=value format. This causes
some information to get lost. The event has been reformatted to follow
the convention. Additionally the audit_enabled value was added for
troubleshooting purposes. The following is an example of the new event:

type=KERNEL audit(1480621249.833:1): state=initialized
audit_enabled=0 res=1

Signed-off-by: Steve Grubb <sgrubb@redhat.com>
[PM: commit tweaks to make checkpatch.pl happy]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: use proper refcount locking on audit_sock

Resetting audit_sock appears to be racy.

audit_sock was being copied and dereferenced without using a refcount on
the source sock.

Bump the refcount on the underlying sock when we store a refrence in
audit_sock and release it when we reset audit_sock. audit_sock
modification needs the audit_cmd_mutex.

See: https://lkml.org/lkml/2016/11/26/232

Thanks to Eric Dumazet <edumazet@google.com> and Cong Wang
<xiyou.wangcong@gmail.com> on ideas how to fix it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
[PM: fixed the comment block text formatting for auditd_reset()]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: don't ever sleep on a command record/message

Sleeping on a command record/message in audit_log_start() could slow
something, e.g. auditd, from doing something important, e.g. clean
shutdown, which could present problems on a heavily loaded system.
This patch allows tasks to bypass any queue restrictions if they are
logging a command record/message.

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

audit: handle a clean auditd shutdown with grace

When auditd stops cleanly it sets 'auditd_pid' to 0 with an
AUDIT_SET message, in this case we should reset our backlog
queues via the auditd_reset() function. This patch also adds
a 'auditd_pid' check to the top of kauditd_send_unicast_skb()
so we can fail quicker.

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

audit: wake up kauditd_thread after auditd registers

This patch was suggested by Richard Briggs back in 2015, see the link
to the mail archive below. Unfortunately, that patch is no longer
even remotely valid due to other changes to the code.

* https://www.redhat.com/archives/linux-audit/2015-October/msg00075.html

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

audit: rework audit_log_start()

The backlog queue handling in audit_log_start() is a little odd with
some questionable design decisions, this patch attempts to rectify
this with the following changes:

* Never make auditd wait, ignore any backlog limits as we need auditd
awake so it can drain the backlog queue.

* When we hit a backlog limit and start dropping records, don't wake
all the tasks sleeping on the backlog, that's silly. Instead, let
kauditd_thread() take care of waking everyone once it has had a chance
to drain the backlog queue.

* Don't keep a global backlog timeout countdown, make it per-task. A
per-task timer means we won't have all the sleeping tasks waking at
the same time and hammering on an already stressed backlog queue.

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

audit: rework the audit queue handling

The audit record backlog queue has always been a bit of a mess, and
the moving the multicast send into kauditd_thread() from
audit_log_end() only makes things worse. This patch attempts to fix
the backlog queue with a better design that should hold up better
under load and have less of a performance impact at syscall
invocation time.

While it looks like there is a log going on in this patch, the main
change is the move from a single backlog queue to three queues:

* A queue for holding records generated from audit_log_end() that
haven't been consumed by kauditd_thread() (audit_queue).

* A queue for holding records that have been sent via multicast but
had a temporary failure when sending via unicast and need a resend
(audit_retry_queue).

* A queue for holding records that haven't been sent via unicast
because no one is listening (audit_hold_queue).

Special care is taken in this patch to ensure that the proper
record ordering is preserved, e.g. we send everything in the hold
queue first, then the retry queue, and finally the main queue.

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

audit: rename the queues and kauditd related functions

The audit queue names can be shortened and the record sending
helpers associated with the kauditd task could be named better, do
these small cleanups now to make life easier once we start reworking
the queues and kauditd code.

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

audit: queue netlink multicast sends just like we do for unicast sends

Sending audit netlink multicast messages is bad for all the same
reasons that sending audit netlink unicast messages is bad, so this
patch reworks things so that we don't do the multicast send in
audit_log_end(), we do it from the dedicated kauditd_thread thread just
as we do for unicast messages.

See the GitHub issues below for more information/history:

* https://github.com/linux-audit/audit-kernel/issues/23
* https://github.com/linux-audit/audit-kernel/issues/22

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

audit: fixup audit_init()

Make sure everything is initialized before we start the kauditd_thread
and don't emit the "initialized" record until everything is finished.
We also panic with a descriptive message if we can't start the
kauditd_thread.

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

audit: move kaudit thread start from auditd registration to kaudit init (#2)

Richard made this change some time ago but Eric backed it out because
the rest of the supporting code wasn't ready. In order to move the
netlink multicast send to kauditd_thread we need to ensure the
kauditd_thread is always running, so restore commit 6ff5e459 ("audit:
move kaudit thread start from auditd registration to kaudit init").

Signed-off-by: Richard Guy Briggs <rbriggs@redhat.com>
[PM: brought forward and merged based on Richard's old patch]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit_log_{name,link_denied}: constify struct path

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

audit: remove useless synchronize_net()

netlink kernel socket is protected by refcount, not RCU.
Its rcv path is neither protected by RCU. So the synchronize_net()
is just pointless.

Cc: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: make struct pernet_operations::id unsigned int

Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

void f(long *p, int i)
{
g(p[i]);
}

roughly translates to

movsx rsi, esi
mov rdi, [rsi+...]
call g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

static inline void *net_generic(const struct net *net, int id)
{
...
ptr = ng->ptr[id - 1];
...
}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
function old new delta
nfsd4_lock 3886 3959 +73
tipc_link_build_proto_msg 1096 1140 +44
mac80211_hwsim_new_radio 2776 2808 +32
tipc_mon_rcv 1032 1058 +26
svcauth_gss_legacy_init 1413 1429 +16
tipc_bcbase_select_primary 379 392 +13
nfsd4_exchange_id 1247 1260 +13
nfsd4_setclientid_confirm 782 793 +11
...
put_client_renew_locked 494 480 -14
ip_set_sockfn_get 730 716 -14
geneve_sock_add 829 813 -16
nfsd4_sequence_done 721 703 -18
nlmclnt_lookup_host 708 686 -22
nfsd4_lockt 1085 1063 -22
nfs_get_client 1077 1050 -27
tcf_bpf_init 1106 1076 -30
nfsd4_encode_fattr 5997 5930 -67
Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: consistently record PIDs with task_tgid_nr()

Unfortunately we record PIDs in audit records using a variety of
methods despite the correct way being the use of task_tgid_nr().
This patch converts all of these callers, except for the case of
AUDIT_SET in audit_receive_msg() (see the comment in the code).

Reported-by: Jeff Vander Stoep <jeffv@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: move audit_get_tty to reduce scope and kabi changes

The only users of audit_get_tty and audit_put_tty are internal to
audit, so move it out of include/linux/audit.h to kernel.h and create
a proper function rather than inlining it. This also reduces kABI
changes.

Suggested-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: line wrapped description]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: add fields to exclude filter by reusing user filter

RFE: add additional fields for use in audit filter exclude rules
https://github.com/linux-audit/audit-kernel/issues/5

Re-factor and combine audit_filter_type() with audit_filter_user() to
use audit_filter_user_rules() to enable the exclude filter to
additionally filter on PID, UID, GID, AUID, LOGINUID_SET, SUBJ_*.

The process of combining the similar audit_filter_user() and
audit_filter_type() functions, required inverting the meaning and
including the ALWAYS action of the latter.

Include audit_filter_user_rules() into audit_filter(), removing
unneeded logic in the process.

Keep the check to quit early if the list is empty.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: checkpatch.pl fixes - whitespace damage, wrapped description]
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit: add tty field to LOGIN event

The tty field was missing from AUDIT_LOGIN events.

Refactor code to create a new function audit_get_tty(), using it to
replace the call in audit_log_task_info() and to add it to
audit_log_set_loginuid(). Lock and bump the kref to protect it, adding
audit_put_tty() alias to decrement it.

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

audit: we don't need to __set_current_state(TASK_RUNNING)

Remove the calls to __set_current_state() to mark the task as running
and do some related cleanup in wait_for_auditd() to limit the amount
of work we do when we aren't going to reschedule the current task.

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

tty: audit: Handle tty audit enable atomically

The audit_tty and audit_tty_log_passwd fields are actually bool
values, so merge into single memory location to access atomically.

NB: audit log operations may still occur after tty audit is disabled
which is consistent with the existing functionality

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: audit: Combine push functions

tty_audit_push() and tty_audit_push_current() perform identical
tasks; eliminate the tty_audit_push() implementation and the
tty_audit_push_current() name.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

audit: log failed attempts to change audit_pid configuration

Failed attempts to change the audit_pid configuration are not presently
logged. One case is an attempt to starve an old auditd by starting up
a new auditd when the old one is still alive and active. The other
case is an attempt to orphan a new auditd when an old auditd shuts
down.

Log both as AUDIT_CONFIG_CHANGE messages with failure result.

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

audit: stop an old auditd being starved out by a new auditd

Nothing prevents a new auditd starting up and replacing a valid
audit_pid when an old auditd is still running, effectively starving out
the old auditd since audit_pid no longer points to the old valid
auditd.

If no message to auditd has been attempted since auditd died
unnaturally or got killed, audit_pid will still indicate it is alive.
There isn't an easy way to detect if an old auditd is still running on
the existing audit_pid other than attempting to send a message to see
if it fails. An -ECONNREFUSED almost certainly means it disappeared
and can be replaced. Other errors are not so straightforward and may
indicate transient problems that will resolve themselves and the old
auditd will recover. Yet others will likely need manual intervention
for which a new auditd will not solve the problem.

Send a new message type (AUDIT_REPLACE) to the old auditd containing a
u32 with the PID of the new auditd. If the audit replace message
succeeds (or doesn't fail with certainty), fail to register the new
auditd and return an error (-EEXIST).

This is expected to make the patch preventing an old auditd orphaning a
new auditd redundant.

V3: Switch audit message type from 1000 to 1300 block.

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

audit: Delete unnecessary checks before two function calls

The functions consume_skb() and kfree_skb() test whether their argument
is NULL and then return immediately.
Thus the tests around their calls are not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[PM: tweak patch prefix]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: wake up threads if queue switched from limited to unlimited

If the audit_backlog_limit is changed from a limited value to an
unlimited value (zero) while the queue was overflowed, wake up the
audit_backlog_wait queue to allow those processes to continue.

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

audit: include auditd's threads in audit_log_start() wait exception

Should auditd spawn threads, allow all members of its thread group to
use the audit_backlog_limit reserves to bypass the queue limits too.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: minor upstream merge tweaks]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: remove audit_backlog_wait_overflow

It seems much more obvious and readable to simply use "0".

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

audit: don't needlessly reset valid wait time

After auditd has recovered from an overflowed queue, the first process
that doesn't use reserves to make it through the queue checks should
reset the audit backlog wait time to the configured value. After that,
there is no need to keep resetting it.

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

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>

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

audit: make audit_log_common_recv_msg() a void function

It always returns zero and no one is checking the return value.

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

audit: removing unused variable

Variable rc in not required as it is just used for unchanged for return,
and return is always 0 in the function.

Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
[PM: fixed spelling errors in description]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: audit_string_contains_control can be boolean

This patch makes audit_string_contains_control return bool to improve
readability due to this particular function only using either one or
zero as its return value.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: try harder to send to auditd upon netlink failure

There are several reports of the kernel losing contact with auditd when
it is, in fact, still running. When this happens, kernel syslogs show:
"audit: *NO* daemon at audit_pid=<pid>"
although auditd is still running, and is apparently happy, listening on
the netlink socket. The pid in the "*NO* daemon" message matches the pid
of the running auditd process. Restarting auditd solves this.

The problem appears to happen randomly, and doesn't seem to be strongly
correlated to the rate of audit events being logged. The problem
happens fairly regularly (every few days), but not yet reproduced to
order.

On production kernels, BUG_ON() is a no-op, so any error will trigger
this.

Commit 34eab0a7cd45 ("audit: prevent an older auditd shutdown from
orphaning a newer auditd startup") eliminates one possible cause. This
isn't the case here, since the PID in the error message and the PID of
the running auditd match.

The primary expected cause of error here is -ECONNREFUSED when the audit
daemon goes away, when netlink_getsockbyportid() can't find the auditd
portid entry in the netlink audit table (or there is no receive
function). If -EPERM is returned, that situation isn't likely to be
resolved in a timely fashion without administrator intervention. In
both cases, reset the audit_pid. This does not rule out a race
condition. SELinux is expected to return zero since this isn't an INET
or INET6 socket. Other LSMs may have other return codes. Log the error
code for better diagnosis in the future.

In the case of -ENOMEM, the situation could be temporary, based on local
or general availability of buffers. -EAGAIN should never happen since
the netlink audit (kernel) socket is set to MAX_SCHEDULE_TIMEOUT.
-ERESTARTSYS and -EINTR are not expected since this kernel thread is not
expected to receive signals. In these cases (or any other unexpected
ones for now), report the error and re-schedule the thread, retrying up
to 5 times.

v2:
Removed BUG_ON().
Moved comma in pr_*() statements.
Removed audit_strerror() text.

Reported-by: Vipin Rathor <v.rathor@gmail.com>
Reported-by: <ctcard@hotmail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: applied rgb's fixup patch to correct audit_log_lost() format issues]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: use macros for unset inode and device values

Clean up a number of places were casted magic numbers are used to represent
unset inode and device numbers in preparation for the audit by executable path
patch set.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: enclosed the _UNSET macros in parentheses for ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: fix for typo in comment to function audit_log_link_denied()


Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

VFS: audit: d_backing_inode() annotations

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

audit: Remove condition which always evaluates to false

After commit 3e1d0bb6224f019893d1c498cc3327559d183674 ("audit: Convert int limit
uses to u32"), by converting an int to u32, few conditions will always evaluate
to false.

These warnings were emitted during compilation:

kernel/audit.c: In function ‘audit_set_enabled’:
kernel/audit.c:347:2: warning: comparison of unsigned expression < 0 is always
false [-Wtype-limits]
if (state < AUDIT_OFF || state > AUDIT_LOCKED)
^
kernel/audit.c: In function ‘audit_receive_msg’:
kernel/audit.c:880:9: warning: comparison of unsigned expression < 0 is
always false [-Wtype-limits]
if (s.backlog_wait_time < 0 ||

The following patch removes those unnecessary conditions.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: reduce mmap_sem hold for mm->exe_file

The mm->exe_file is currently serialized with mmap_sem (shared)
in order to both safely (1) read the file and (2) audit it via
audit_log_d_path(). Good users will, on the other hand, make use
of the more standard get_mm_exe_file(), requiring only holding
the mmap_sem to read the value, and relying on reference counting
to make sure that the exe file won't dissapear underneath us.

Additionally, upon NULL return of get_mm_exe_file, we also call
audit_log_format(ab, " exe=(null)").

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: consolidate handling of mm->exe_file

This patch adds a audit_log_d_path_exe() helper function
to share how we handle auditing of the exe_file's path.
Used by both audit and auditsc. No functionality is changed.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: code clean up

Fixed a coding style issue (unnecessary parentheses , unnecessary braces)

Signed-off-by: Ameen-Ali <Ameenali023@gmail.com>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: don't reset working wait time accidentally with auditd

During a queue overflow condition while we are waiting for auditd to drain the
queue to make room for regular messages, we don't want a successful auditd that
has bypassed the queue check to reset the backlog wait time.

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

audit: don't lose set wait time on first successful call to audit_log_start()

Copy the set wait time to a working value to avoid losing the set
value if the queue overflows.

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

netlink/genetlink: pass network namespace to bind/unbind

Netlink families can exist in multiple namespaces, and for the most
part multicast subscriptions are per network namespace. Thus it only
makes sense to have bind/unbind notifications per network namespace.

To achieve this, pass the network namespace of a given client socket
to the bind/unbind functions.

Also do this in generic netlink, and there also make sure that any
bind for multicast groups that only exist in init_net is rejected.
This isn't really a problem if it is accepted since a client in a
different namespace will never receive any notifications from such
a group, but it can confuse the family if not rejected (it's also
possible to silently (without telling the family) accept it, but it
would also have to be ignored on unbind so families that take any
kind of action on bind/unbind won't do unnecessary work for invalid
clients like that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: use supplied gfp_mask from audit_buffer in kauditd_send_multicast_skb

Eric Paris explains: Since kauditd_send_multicast_skb() gets called in
audit_log_end(), which can come from any context (aka even a sleeping context)
GFP_KERNEL can't be used. Since the audit_buffer knows what context it should
use, pass that down and use that.

See: https://lkml.org/lkml/2014/12/16/542

BUG: sleeping function called from invalid context at mm/slab.c:2849
in_atomic(): 1, irqs_disabled(): 0, pid: 885, name: sulogin
2 locks held by sulogin/885:
#0: (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff91152e30>] prepare_bprm_creds+0x28/0x8b
#1: (tty_files_lock){+.+.+.}, at: [<ffffffff9123e787>] selinux_bprm_committing_creds+0x55/0x22b
CPU: 1 PID: 885 Comm: sulogin Not tainted 3.18.0-next-20141216 #30
Hardware name: Dell Inc. Latitude E6530/07Y85M, BIOS A15 06/20/2014
ffff880223744f10 ffff88022410f9b8 ffffffff916ba529 0000000000000375
ffff880223744f10 ffff88022410f9e8 ffffffff91063185 0000000000000006
0000000000000000 0000000000000000 0000000000000000 ffff88022410fa38
Call Trace:
[<ffffffff916ba529>] dump_stack+0x50/0xa8
[<ffffffff91063185>] ___might_sleep+0x1b6/0x1be
[<ffffffff910632a6>] __might_sleep+0x119/0x128
[<ffffffff91140720>] cache_alloc_debugcheck_before.isra.45+0x1d/0x1f
[<ffffffff91141d81>] kmem_cache_alloc+0x43/0x1c9
[<ffffffff914e148d>] __alloc_skb+0x42/0x1a3
[<ffffffff914e2b62>] skb_copy+0x3e/0xa3
[<ffffffff910c263e>] audit_log_end+0x83/0x100
[<ffffffff9123b8d3>] ? avc_audit_pre_callback+0x103/0x103
[<ffffffff91252a73>] common_lsm_audit+0x441/0x450
[<ffffffff9123c163>] slow_avc_audit+0x63/0x67
[<ffffffff9123c42c>] avc_has_perm+0xca/0xe3
[<ffffffff9123dc2d>] inode_has_perm+0x5a/0x65
[<ffffffff9123e7ca>] selinux_bprm_committing_creds+0x98/0x22b
[<ffffffff91239e64>] security_bprm_committing_creds+0xe/0x10
[<ffffffff911515e6>] install_exec_creds+0xe/0x79
[<ffffffff911974cf>] load_elf_binary+0xe36/0x10d7
[<ffffffff9115198e>] search_binary_handler+0x81/0x18c
[<ffffffff91153376>] do_execveat_common.isra.31+0x4e3/0x7b7
[<ffffffff91153669>] do_execve+0x1f/0x21
[<ffffffff91153967>] SyS_execve+0x25/0x29
[<ffffffff916c61a9>] stub_execve+0x69/0xa0

Cc: stable@vger.kernel.org #v3.16-rc1
Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Tested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: convert status version to a feature bitmap

The version field defined in the audit status structure was found to have
limitations in terms of its expressibility of features supported. This is
distict from the get/set features call to be able to command those features
that are present.

Converting this field from a version number to a feature bitmap will allow
distributions to selectively backport and support certain features and will
allow upstream to be able to deprecate features in the future. It will allow
userspace clients to first query the kernel for which features are actually
present and supported. Currently, EINVAL is returned rather than EOPNOTSUP,
which isn't helpful in determining if there was an error in the command, or if
it simply isn't supported yet. Past features are not represented by this
bitmap, but their use may be converted to EOPNOTSUP if needed in the future.

Since "version" is too generic to convert with a #define, use a union in the
struct status, introducing the member "feature_bitmap" unionized with
"version".

Convert existing AUDIT_VERSION_* macros over to AUDIT_FEATURE_BITMAP*
counterparts, leaving the former for backwards compatibility.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: minor whitespace tweaks]
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit, sched/wait: Fixup kauditd_thread() wait loop

The kauditd_thread wait loop is a bit iffy; it has a number of problems:

- calls try_to_freeze() before schedule(); you typically want the
thread to re-evaluate the sleep condition when unfreezing, also
freeze_task() issues a wakeup.

- it unconditionally does the {add,remove}_wait_queue(), even when the
sleep condition is false.

Use wait_event_freezable() that does the right thing.

Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: oleg@redhat.com
Cc: Eric Paris <eparis@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20141002102251.GA6324@worktop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

audit: AUDIT_FEATURE_CHANGE message format missing delimiting space

Add a space between subj= and feature= fields to make them parsable.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>

audit: get comm using lock to avoid race in string printing

When task->comm is passed directly to audit_log_untrustedstring() without
getting a copy or using the task_lock, there is a race that could happen that
would output a NULL (\0) in the output string that would effectively truncate
the rest of the report text after the comm= field in the audit, losing fields.

Use get_task_comm() to get a copy while acquiring the task_lock to prevent
this and to prevent the result from being a mixture of old and new values of
comm.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: correct AUDIT_GET_FEATURE return message type

When an AUDIT_GET_FEATURE message is sent from userspace to the kernel, it
should reply with a message tagged as an AUDIT_GET_FEATURE type with a struct
audit_feature. The current reply is a message tagged as an AUDIT_GET
type with a struct audit_feature.

This appears to have been a cut-and-paste-eo in commit b0fed40.

Reported-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: set nlmsg_len for multicast messages.

Report:
Looking at your example code in
http://people.redhat.com/rbriggs/audit-multicast-listen/audit-multicast-listen.c,
it seems that nlmsg_len field in the received messages is supposed to
contain the length of the header + payload, but it is always set to the
size of the header only, i.e. 16. The example program works, because
the printf format specifies the minimum width, not "precision", so it
simply prints out the payload until the first zero byte. This isn't too
much of a problem, but precludes the use of recvmmsg, iiuc?

(gdb) p *(struct nlmsghdr*)nlh
$14 = {nlmsg_len = 16, nlmsg_type = 1100, nlmsg_flags = 0, nlmsg_seq = 0, nlmsg_pid = 9910}

The only time nlmsg_len would have been updated was at audit_buffer_alloc()
inside audit_log_start() and never updated after. It should arguably be done
in audit_log_vformat(), but would be more efficient in audit_log_end().

Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: use atomic_t to simplify audit_serial()

Since there is already a primitive to do this operation in the atomic_t, use it
to simplify audit_serial().

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

kernel/audit.c: use ARRAY_SIZE instead of sizeof/sizeof[0]

Use kernel.h definition.

Cc: Eric Paris <eparis@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: reduce scope of audit_log_fcaps

audit_log_fcaps() isn't used outside kernel/audit.c. Reduce its scope.

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

audit: reduce scope of audit_net_id

audit_net_id isn't used outside kernel/audit.c. Reduce its scope.

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

CAPABILITIES: remove undefined caps from all processes

This is effectively a revert of 7b9a7ec565505699f503b4fcf61500dceb36e744
plus fixing it a different way...

We found, when trying to run an application from an application which
had dropped privs that the kernel does security checks on undefined
capability bits. This was ESPECIALLY difficult to debug as those
undefined bits are hidden from /proc/$PID/status.

Consider a root application which drops all capabilities from ALL 4
capability sets. We assume, since the application is going to set
eff/perm/inh from an array that it will clear not only the defined caps
less than CAP_LAST_CAP, but also the higher 28ish bits which are
undefined future capabilities.

The BSET gets cleared differently. Instead it is cleared one bit at a
time. The problem here is that in security/commoncap.c::cap_task_prctl()
we actually check the validity of a capability being read. So any task
which attempts to 'read all things set in bset' followed by 'unset all
things set in bset' will not even attempt to unset the undefined bits
higher than CAP_LAST_CAP.

So the 'parent' will look something like:
CapInh: 0000000000000000
CapPrm: 0000000000000000
CapEff: 0000000000000000
CapBnd: ffffffc000000000

All of this 'should' be fine. Given that these are undefined bits that
aren't supposed to have anything to do with permissions. But they do...

So lets now consider a task which cleared the eff/perm/inh completely
and cleared all of the valid caps in the bset (but not the invalid caps
it couldn't read out of the kernel). We know that this is exactly what
the libcap-ng library does and what the go capabilities library does.
They both leave you in that above situation if you try to clear all of
you capapabilities from all 4 sets. If that root task calls execve()
the child task will pick up all caps not blocked by the bset. The bset
however does not block bits higher than CAP_LAST_CAP. So now the child
task has bits in eff which are not in the parent. These are
'meaningless' undefined bits, but still bits which the parent doesn't
have.

The problem is now in cred_cap_issubset() (or any operation which does a
subset test) as the child, while a subset for valid cap bits, is not a
subset for invalid cap bits! So now we set durring commit creds that
the child is not dumpable. Given it is 'more priv' than its parent. It
also means the parent cannot ptrace the child and other stupidity.

The solution here:
1) stop hiding capability bits in status
This makes debugging easier!

2) stop giving any task undefined capability bits. it's simple, it you
don't put those invalid bits in CAP_FULL_SET you won't get them in init
and you won't get them in any other task either.
This fixes the cap_issubset() tests and resulting fallout (which
made the init task in a docker container untraceable among other
things)

3) mask out undefined bits when sys_capset() is called as it might use
~0, ~0 to denote 'all capabilities' for backward/forward compatibility.
This lets 'capsh --caps="all=eip" -- -c /bin/bash' run.

4) mask out undefined bit when we read a file capability off of disk as
again likely all bits are set in the xattr for forward/backward
compatibility.
This lets 'setcap all+pe /bin/bash; /bin/bash' run

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Dan Walsh <dwalsh@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>

ipc, kernel: use Linux headers

Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
Use #include <linux/types.h> instead of <asm/types.h>

Signed-off-by: Paul McQuade <paulmcquad@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net: Use netlink_ns_capable to verify the permisions of netlink messages

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: send multicast messages only if there are listeners

Test first to see if there are any userspace multicast listeners bound to the
socket before starting the multicast send work.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: add netlink multicast group for log read

Add a netlink multicast socket with one group to kaudit for "best-effort"
delivery to read-only userspace clients such as systemd, in addition to the
existing bidirectional unicast auditd userspace client.

Currently, auditd is intended to use the CAP_AUDIT_CONTROL and CAP_AUDIT_WRITE
capabilities, but actually uses CAP_NET_ADMIN. The CAP_AUDIT_READ capability
is added for use by read-only AUDIT_NLGRP_READLOG netlink multicast group
clients to the kaudit subsystem.

This will safely give access to services such as systemd to consume audit logs
while ensuring write access remains restricted for integrity.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: add netlink audit protocol bind to check capabilities on multicast join

Register a netlink per-protocol bind fuction for audit to check userspace
process capabilities before allowing a multicast group connection.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

AUDIT: Allow login in non-init namespaces

It its possible to configure your PAM stack to refuse login if audit
messages (about the login) were unable to be sent. This is common in
many distros and thus normal configuration of many containers. The PAM
modules determine if audit is enabled/disabled in the kernel based on
the return value from sending an audit message on the netlink socket.
If userspace gets back ECONNREFUSED it believes audit is disabled in the
kernel. If it gets any other error else it refuses to let the login
proceed.

Just about ever since the introduction of namespaces the kernel audit
subsystem has returned EPERM if the task sending a message was not in
the init user or pid namespace. So many forms of containers have never
worked if audit was enabled in the kernel.

BUT if the container was not in net_init then the kernel network code
would send ECONNREFUSED (instead of the audit code sending EPERM). Thus
by pure accident/dumb luck/bug if an admin configured the PAM stack to
reject all logins that didn't talk to audit, but then ran the login
untility in the non-init_net namespace, it would work!! Clearly this was
a bug, but it is a bug some people expected.

With the introduction of network namespace support in 3.14-rc1 the two
bugs stopped cancelling each other out. Now, containers in the
non-init_net namespace refused to let users log in (just like PAM was
configfured!) Obviously some people were not happy that what used to let
users log in, now didn't!

This fix is kinda hacky. We return ECONNREFUSED for all non-init
relevant namespaces. That means that not only will the old broken
non-init_net setups continue to work, now the broken non-init_pid or
non-init_user setups will 'work'. They don't really work, since audit
isn't logging things. But it's what most users want.

In 3.15 we should have patches to support not only the non-init_net
(3.14) namespace but also the non-init_pid and non-init_user namespace.
So all will be right in the world. This just opens the doors wide open
on 3.14 and hopefully makes users happy, if not the audit system...

Reported-by: Andre Tomt <andre@tomt.net>
Reported-by: Adam Richter <adam_richter2004@yahoo.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:
kernel/audit.c

AUDIT: Allow login in non-init namespaces

It its possible to configure your PAM stack to refuse login if audit
messages (about the login) were unable to be sent. This is common in
many distros and thus normal configuration of many containers. The PAM
modules determine if audit is enabled/disabled in the kernel based on
the return value from sending an audit message on the netlink socket.
If userspace gets back ECONNREFUSED it believes audit is disabled in the
kernel. If it gets any other error else it refuses to let the login
proceed.

Just about ever since the introduction of namespaces the kernel audit
subsystem has returned EPERM if the task sending a message was not in
the init user or pid namespace. So many forms of containers have never
worked if audit was enabled in the kernel.

BUT if the container was not in net_init then the kernel network code
would send ECONNREFUSED (instead of the audit code sending EPERM). Thus
by pure accident/dumb luck/bug if an admin configured the PAM stack to
reject all logins that didn't talk to audit, but then ran the login
untility in the non-init_net namespace, it would work!! Clearly this was
a bug, but it is a bug some people expected.

With the introduction of network namespace support in 3.14-rc1 the two
bugs stopped cancelling each other out. Now, containers in the
non-init_net namespace refused to let users log in (just like PAM was
configfured!) Obviously some people were not happy that what used to let
users log in, now didn't!

This fix is kinda hacky. We return ECONNREFUSED for all non-init
relevant namespaces. That means that not only will the old broken
non-init_net setups continue to work, now the broken non-init_pid or
non-init_user setups will 'work'. They don't really work, since audit
isn't logging things. But it's what most users want.

In 3.15 we should have patches to support not only the non-init_net
(3.14) namespace but also the non-init_pid and non-init_user namespace.
So all will be right in the world. This just opens the doors wide open
on 3.14 and hopefully makes users happy, if not the audit system...

Reported-by: Andre Tomt <andre@tomt.net>
Reported-by: Adam Richter <adam_richter2004@yahoo.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c

This patch replaces rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL)

The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure.
And in the case of the NULL pointer, there is no structure to initialize.
So, rcu_assign_pointer(p, NULL) can be safely converted to RCU_INIT_POINTER(p, NULL)

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: remove stray newlines from audit_log_lost messages

Calling audit_log_lost with a \n in the format string leads to extra
newlines in dmesg. That function will eventually call audit_panic which
uses pr_err with an explicit \n included. Just make these calls match the
others that lack \n.

Reported-by: Jonathan Kamens <jik@kamens.brookline.ma.us>
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: allow user processes to log from another PID namespace

Still only permit the audit logging daemon and control to operate from the
initial PID namespace, but allow processes to log from another PID namespace.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
(informed by ebiederman's c776b5d2)

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

audit: anchor all pid references in the initial pid namespace

Store and log all PIDs with reference to the initial PID namespace and
use the access functions task_pid_nr() and task_tgid_nr() for task->pid
and task->tgid.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
(informed by ebiederman's c776b5d2)
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: convert PPIDs to the inital PID namespace.

sys_getppid() returns the parent pid of the current process in its own pid
namespace. Since audit filters are based in the init pid namespace, a process
could avoid a filter or trigger an unintended one by being in an alternate pid
namespace or log meaningless information.

Switch to task_ppid_nr() for PPIDs to anchor all audit filters in the
init_pid_ns.

(informed by ebiederman's 6c621b7e)
Cc: stable@vger.kernel.org
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

audit: Send replies in the proper network namespace.

In perverse cases of file descriptor passing the current network
namespace of a process and the network namespace of a socket used by
that socket may differ. Therefore use the network namespace of the
appropiate socket to ensure replies always go to the appropiate
socket.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: Use struct net not pid_t to remember the network namespce to reply in

While reading through 3.14-rc1 I found a pretty siginficant mishandling
of network namespaces in the recent audit changes.

In struct audit_netlink_list and audit_reply add a reference to the
network namespace of the caller and remove the userspace pid of the
caller. This cleanly remembers the callers network namespace, and
removes a huge class of races and nasty failure modes that can occur
when attempting to relook up the callers network namespace from a pid_t
(including the caller's network namespace changing, pid wraparound, and
the pid simply not being present).

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: Update kdoc for audit_send_reply and audit_list_rules_send

The kbuild test robot reported:
> tree: git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git for-next
> head: 6f285b19d09f72e801525f5eea1bdad22e559bf0
> commit: 6f285b19d09f72e801525f5eea1bdad22e559bf0 [2/2] audit: Send replies in the proper network namespace.
> reproduce: make htmldocs
>
> >> Warning(kernel/audit.c:575): No description found for parameter 'request_skb'
> >> Warning(kernel/audit.c:575): Excess function parameter 'portid' description in 'audit_send_reply'
> >> Warning(kernel/auditfilter.c:1074): No description found for parameter 'request_skb'
> >> Warning(kernel/auditfilter.c:1074): Excess function parameter 'portid' description in 'audit_list_rules_s

Which was caused by my failure to update the kdoc annotations when I
updated the functions. Fix that small oversight now.

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

audit: Send replies in the proper network namespace.

In perverse cases of file descriptor passing the current network
namespace of a process and the network namespace of a socket used by
that socket may differ. Therefore use the network namespace of the
appropiate socket to ensure replies always go to the appropiate
socket.

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

audit: Use struct net not pid_t to remember the network namespce to reply in

In struct audit_netlink_list and audit_reply add a reference to the
network namespace of the caller and remove the userspace pid of the
caller. This cleanly remembers the callers network namespace, and
removes a huge class of races and nasty failure modes that can occur
when attempting to relook up the callers network namespace from a
pid_t (including the caller's network namespace changing, pid
wraparound, and the pid simply not being present).

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

audit: fix location of __net_initdata for audit_net_ops

Fixup caught by checkpatch.

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

audit: remove pr_info for every network namespace

A message about creating the audit socket might be fine at startup, but
a pr_info for every single network namespace created on a system isn't
useful.

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

audit: Convert int limit uses to u32

The equivalent uapi struct uses __u32 so make the kernel
uses u32 too.

This can prevent some oddities where the limit is
logged/emitted as a negative value.

Convert kstrtol to kstrtouint to disallow negative values.

Signed-off-by: Joe Perches <joe@perches.com>
[eparis: do not remove static from audit_default declaration]

audit: Use more current logging style

Add pr_fmt to prefix "audit: " to output
Convert printk(KERN_<LEVEL> to pr_<level>
Coalesce formats
Use pr_cont
Move a brace after switch

Signed-off-by: Joe Perches <joe@perches.com>

audit: Use hex_byte_pack_upper

Using the generic kernel function causes the
object size to increase with gcc 4.8.1.

$ size kernel/audit.o*
text data bss dec hex filename
18577 6079 8436 33092 8144 kernel/audit.o.new
18579 6015 8420 33014 80f6 kernel/audit.o.old

Unsigned...

audit: reorder AUDIT_TTY_SET arguments

An admin is likely to want to see old and new values next to each other.
Putting all of the old values followed by all of the new values is just
hard to read as a human.

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

audit: rework AUDIT_TTY_SET to only grab spin_lock once

We can simplify the AUDIT_TTY_SET code to only grab the spin_lock one
time. We need to determine if the new values are valid and if so, set
the new values at the same time we grab the old onces. While we are
here get rid of 'res' and just use err.

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

audit: remove needless switch in AUDIT_SET

If userspace specified that it was setting values via the mask we do not
need a second check to see if they also set the version field high
enough to understand those values. (clearly if they set the mask they
knew those values).

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

audit: use define's for audit version

Give names to the audit versions. Just something for a userspace
programmer to know what the version provides.

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

audit: wait_for_auditd rework for readability

We had some craziness with signed to unsigned long casting which appears
wholely unnecessary. Just use signed long. Even though 2 values of the
math equation are unsigned longs the result is expected to be a signed
long. So why keep casting the result to signed long? Just make it
signed long and use it.

We also remove the needless "timeout" variable. We already have the
stack "sleep_time" variable. Just use that...

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

audit: log task info on feature change

Add task information to the log when changing a feature state.

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

audit: fix incorrect set of audit_sock

NETLINK_CB(skb).sk is the socket of user space process,
netlink_unicast in kauditd_send_skb wants the kernel
side socket. Since the sk_state of audit netlink socket
is not NETLINK_CONNECTED, so the netlink_getsockbyportid
doesn't return -ECONNREFUSED.

And the socket of userspace process can be released anytime,
so the audit_sock may point to invalid socket.

this patch sets the audit_sock to the kernel side audit
netlink socket.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: print error message when fail to create audit socket

print the error message and then return -ENOMEM.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: log on errors from filter user rules

An error on an AUDIT_NEVER rule disabled logging on that rule.
On error on AUDIT_NEVER rules, log.

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

audit: audit_log_start running on auditd should not stop

The backlog cannot be consumed when audit_log_start is running on auditd
even if audit_log_start calls wait_for_auditd to consume it.
The situation is the deadlock because only auditd can consume the backlog.
If the other process needs to send the backlog, it can be also stopped
by the deadlock.

So, audit_log_start running on auditd should not stop.

You can see the deadlock with the following reproducer:
# auditctl -a exit,always -S all
# reboot

Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Reviewed-by: gaofeng@cn.fujitsu.com
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: drop audit_cmd_lock in AUDIT_USER family of cases

We do not need to hold the audit_cmd_mutex for this family of cases. The
possible exception to this is the call to audit_filter_user(), so drop the lock
immediately after. To help in fixing the race we are trying to avoid, make
sure that nothing called by audit_filter_user() calls audit_log_start(). In
particular, watch out for *_audit_rule_match().

This fix will take care of systemd and anything USING audit. It still means
that we could race with something configuring audit and auditd shutting down.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reported-by: toshi.okajima@jp.fujitsu.com
Tested-by: toshi.okajima@jp.fujitsu.com
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: convert all sessionid declaration to unsigned int

Right now the sessionid value in the kernel is a combination of u32,
int, and unsigned int. Just use unsigned int throughout.

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

audit: Added exe field to audit core dump signal log

Currently when the coredump signals are logged by the audit system, the
actual path to the executable is not logged. Without details of exe, the
system admin may not have an exact idea on what program failed.

This patch changes the audit_log_task() so that the path to the exe is also
logged.

This was copied from audit_log_task_info() and the latter enhanced to avoid
disappearing text fields.

Signed-off-by: Paul Davies C <pauldaviesc@gmail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: prevent an older auditd shutdown from orphaning a newer auditd startup

There have been reports of auditd restarts resulting in kaudit not being able
to find a newly registered auditd. It results in reports such as:
kernel: [ 2077.233573] audit: *NO* daemon at audit_pid=1614
kernel: [ 2077.234712] audit: audit_lost=97 audit_rate_limit=0 audit_backlog_limit=320
kernel: [ 2077.234718] audit: auditd disappeared
(previously mis-spelled "dissapeared")

One possible cause is a race between the shutdown of an older auditd and a
newer one. If the newer one sets the daemon pid to itself in kauditd before
the older one has cleared the daemon pid, the newer daemon pid will be erased.
This could be caused by an automated system, or by manual intervention, but in
either case, there is no use in having the older daemon clear the daemon pid
reference since its old pid is no longer being referenced. This patch will
prevent that specific case, returning an error of EACCES.

The case for preventing a newer auditd from registering itself if there is an
existing auditd is a more difficult case that is beyond the scope of this
patch.

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

audit: refactor audit_receive_msg() to clarify AUDIT_*_RULE* cases

audit_receive_msg() needlessly contained a fallthrough case that called
audit_receive_filter(), containing no common code between the cases. Separate
them to make the logic clearer. Refactor AUDIT_LIST_RULES, AUDIT_ADD_RULE,
AUDIT_DEL_RULE cases to create audit_rule_change(), audit_list_rules_send()
functions. This should not functionally change the logic.

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

audit: log AUDIT_TTY_SET config changes

Log transition of config changes when AUDIT_TTY_SET is called, including both
enabled and log_passwd values now in the struct.

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

audit: get rid of *NO* daemon at audit_pid=0 message

kauditd_send_skb is called after audit_pid was checked to be non-zero.

However, it can be set to 0 due to auditd exiting while kauditd_send_skb
is still executed and this can result in a spurious warning about missing
auditd.

Re-check audit_pid before printing the message.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: allow unlimited backlog queue

Since audit can already be disabled by "audit=0" on the kernel boot line, or by
the command "auditctl -e 0", it would be more useful to have the
audit_backlog_limit set to zero mean effectively unlimited (limited only by
system RAM).

Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: use old_lock in audit_set_feature

we already have old_lock, no need to calculate it again.

Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: don't generate audit feature changed log when audit disabled

If audit is disabled,we shouldn't generate the audit log.

Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: fix incorrect order of log new and old feature

The order of new feature and old feature is incorrect,
this patch fix it.

Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: remove useless code in audit_enable

Since kernel parameter is operated before
initcall, so the audit_initialized must be
AUDIT_UNINITIALIZED or DISABLED in audit_enable.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: add audit_backlog_wait_time configuration option

reaahead-collector abuses the audit logging facility to discover which files
are accessed at boot time to make a pre-load list

Add a tuning option to audit_backlog_wait_time so that if auditd can't keep up,
or gets blocked, the callers won't be blocked.

Bump audit_status API version to "2".

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

audit: clean up AUDIT_GET/SET local variables and future-proof API

Re-named confusing local variable names (status_set and status_get didn't agree
with their command type name) and reduced their scope.

Future-proof API changes by not depending on the exact size of the audit_status
struct and by adding an API version field.

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

audit: add kernel set-up parameter to override default backlog limit

The default audit_backlog_limit is 64. This was a reasonable limit at one time.

systemd causes so much audit queue activity on startup that auditd doesn't
start before the backlog queue has already overflowed by more than a factor of
2. On a system with audit= not set on the kernel command line, this isn't an
issue since that history isn't kept for auditd when it is available. On a
system with audit=1 set on the kernel command line, kaudit tries to keep that
history until auditd is able to drain the queue.

This default can be changed by the "-b" option in audit.rules once the system
has booted, but won't help with lost messages on boot.

One way to solve this would be to increase the default backlog queue size to
avoid losing any messages before auditd is able to consume them. This would
be overkill to the embedded community and insufficient for some servers.

Another way to solve it might be to add a kconfig option to set the default
based on the system type. An embedded system would get the current (or
smaller) default, while Workstations might get more than now and servers might
get more.

None of these solutions helps if a system's compiled default is too small to
see the lost messages without compiling a new kernel.

This patch adds a kernel set-up parameter (audit already has one to
enable/disable it) "audit_backlog_limit=<n>" that overrides the default to
allow the system administrator to set the backlog limit.

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

audit: efficiency fix 2: request exclusive wait since all need same resource

These and similar errors were seen on a patched 3.8 kernel when the
audit subsystem was overrun during boot:

udevd[876]: worker [887] unexpectedly returned with status 0x0100
udevd[876]: worker [887] failed while handling
'/devices/pci0000:00/0000:00:03.0/0000:40:00.0'
udevd[876]: worker [880] unexpectedly returned with status 0x0100
udevd[876]: worker [880] failed while handling
'/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1'

udevadm settle - timeout of 180 seconds reached, the event queue
contains:
/sys/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1 (3995)
/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/INT3F0D:00 (4034)

audit: audit_backlog=258 > audit_backlog_limit=256
audit: audit_lost=1 audit_rate_limit=0 audit_backlog_limit=256

The change below increases the efficiency of the audit code and prevents it
from being overrun:

Use add_wait_queue_exclusive() in wait_for_auditd() to put the
thread on the wait queue. When kauditd dequeues an skb, all
of the waiting threads are waiting for the same resource, but
only one is going to get it, so there's no need to wake up
more than one waiter.

See: https://lkml.org/lkml/2013/9/2/479

Signed-off-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: efficiency fix 1: only wake up if queue shorter than backlog limit

These and similar errors were seen on a patched 3.8 kernel when the
audit subsystem was overrun during boot:

udevd[876]: worker [887] unexpectedly returned with status 0x0100
udevd[876]: worker [887] failed while handling
'/devices/pci0000:00/0000:00:03.0/0000:40:00.0'
udevd[876]: worker [880] unexpectedly returned with status 0x0100
udevd[876]: worker [880] failed while handling
'/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1'

udevadm settle - timeout of 180 seconds reached, the event queue
contains:
/sys/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1 (3995)
/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/INT3F0D:00 (4034)

audit: audit_backlog=258 > audit_backlog_limit=256
audit: audit_lost=1 audit_rate_limit=0 audit_backlog_limit=256

The change below increases the efficiency of the audit code and prevents it
from being overrun:

Only issue a wake_up in kauditd if the length of the skb queue is less than the
backlog limit. Otherwise, threads waiting in wait_for_auditd() will simply
wake up, discover that the queue is still too long for them to proceed, and go
back to sleep. This results in wasted context switches and machine cycles.
kauditd_thread() is the only function that removes buffers from audit_skb_queue
so we can't race. If we did, the timeout in wait_for_auditd() would expire and
the waiting thread would continue.

See: https://lkml.org/lkml/2013/9/2/479

Signed-off-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: make use of remaining sleep time from wait_for_auditd

If wait_for_auditd() times out, go immediately to the error function rather
than retesting the loop conditions.

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

audit: reset audit backlog wait time after error recovery

When the audit queue overflows and times out (audit_backlog_wait_time), the
audit queue overflow timeout is set to zero. Once the audit queue overflow
timeout condition recovers, the timeout should be reset to the original value.

See also:
https://lkml.org/lkml/2013/9/2/473

Cc: stable@vger.kernel.org # v3.8-rc4+
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Dan Duval <dan.duval@oracle.com>
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: listen in all network namespaces

Convert audit from only listening in init_net to use register_pernet_subsys()
to dynamically manage the netlink socket list.

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

audit: restore order of tty and ses fields in log output

When being refactored from audit_log_start() to audit_log_task_info(), in
commit e23eb920 the tty and ses fields in the log output got transposed.
Restore to original order to avoid breaking search tools.

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

audit: fix netlink portid naming and types

Normally, netlink ports use the PID of the userspace process as the port ID.
If the PID is already in use by a port, the kernel will allocate another port
ID to avoid conflict. Re-name all references to netlink ports from pid to
portid to reflect this reality and avoid confusion with actual PIDs. Ports
use the __u32 type, so re-type all portids accordingly.

(This patch is very similar to ebiederman's 5deadd69)

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: log the audit_names record type

...to make it clear what the intent behind each record's operation was.

In many cases you can infer this, based on the context of the syscall
and the result. In other cases it's not so obvious. For instance, in
the case where you have a file being renamed over another, you'll have
two different records with the same filename but different inode info.
By logging this information we can clearly tell which one was created
and which was deleted.

This fixes what was broken in commit bfcec708.
Commit 79f6530c should also be backported to stable v3.7+.

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

audit: use given values in tty_audit enable api

In send/GET, we don't want the kernel to lie about what value is set.

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

audit: use nlmsg_len() to get message payload length

Using the nlmsg_len member of the netlink header to test if the message
is valid is wrong as it includes the size of the netlink header itself.
Thereby allowing to send short netlink messages that pass those checks.

Use nlmsg_len() instead to test for the right message length. The result
of nlmsg_len() is guaranteed to be non-negative as the netlink message
already passed the checks of nlmsg_ok().

Also switch to min_t() to please checkpatch.pl.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org # v2.6.6+ for the 1st hunk, v2.6.23+ for the 2nd
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: use memset instead of trying to initialize field by field

We currently are setting fields to 0 to initialize the structure
declared on the stack. This is a bad idea as if the structure has holes
or unpacked space these will not be initialized. Just use memset. This
is not a performance critical section of code.

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

audit: fix info leak in AUDIT_GET requests

We leak 4 bytes of kernel stack in response to an AUDIT_GET request as
we miss to initialize the mask member of status_set. Fix that.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org # v2.6.6+
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: audit feature to set loginuid immutable

This adds a new 'audit_feature' bit which allows userspace to set it
such that the loginuid is absolutely immutable, even if you have
CAP_AUDIT_CONTROL.

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

audit: audit feature to only allow unsetting the loginuid

This is a new audit feature which only grants processes with
CAP_AUDIT_CONTROL the ability to unset their loginuid. They cannot
directly set it from a valid uid to another valid uid. The ability to
unset the loginuid is nice because a priviledged task, like that of
container creation, can unset the loginuid and then priv is not needed
inside the container when a login daemon needs to set the loginuid.

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

audit: implement generic feature setting and retrieving

The audit_status structure was not designed with extensibility in mind.
Define a new AUDIT_SET_FEATURE message type which takes a new structure
of bits where things can be enabled/disabled/locked one at a time. This
structure should be able to grow in the future while maintaining forward
and backward compatibility (based loosly on the ideas from capabilities
and prctl)

This does not actually add any features, but is just infrastructure to
allow new on/off types of audit system features.

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

audit: printk USER_AVC messages when audit isn't enabled

When the audit=1 kernel parameter is absent and auditd is not running,
AUDIT_USER_AVC messages are being silently discarded.

AUDIT_USER_AVC messages should be sent to userspace using printk(), as
mentioned in the commit message of 4a4cd633 ("AUDIT: Optimise the
audit-disabled case for discarding user messages").

When audit_enabled is 0, audit_receive_msg() discards all user messages
except for AUDIT_USER_AVC messages. However, audit_log_common_recv_msg()
refuses to allocate an audit_buffer if audit_enabled is 0. The fix is to
special case AUDIT_USER_AVC messages in both functions.

It looks like commit 50397bd1 ("[AUDIT] clean up audit_receive_msg()")
introduced this bug.

Cc: <stable@kernel.org> # v2.6.25+
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

Audit: remove duplicate comments

Remove it.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: remove newline accidentally added during session id helper refactor

A newline was accidentally added during session ID helper refactorization in
commit 4d3fb709. This needlessly uses up buffer space, messes up syslog
formatting and makes userspace processing less efficient. Remove it.

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

audit: remove duplicate inclusion of the netlink header

Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: format user messages to size of MAX_AUDIT_MESSAGE_LENGTH

Messages of type AUDIT_USER_TTY were being formatted to 1024 octets,
truncating messages approaching MAX_AUDIT_MESSAGE_LENGTH (8970 octets).

Set the formatting to 8560 characters, given maximum estimates for prefix and
suffix budgets.

See the problem discussion:
https://www.redhat.com/archives/linux-audit/2009-January/msg00030.html

And the new size rationale:
https://www.redhat.com/archives/linux-audit/2013-September/msg00016.html

Test ~8k messages with:
auditctl -m "$(for i in $(seq -w 001 820);do echo -n "${i}0______";done)"

Reported-by: LC Bruzenak <lenny@magitekltd.com>
Reported-by: Justin Stephenson <jstephen@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: fix endless wait in audit_log_start()

After commit 829199197a43 ("kernel/audit.c: avoid negative sleep
durations") audit emitters will block forever if userspace daemon cannot
handle backlog.

After the timeout the waiting loop turns into busy loop and runs until
daemon dies or returns back to work. This is a minimal patch for that
bug.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Richard Guy Briggs <rgb@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Chuck Anderson <chuck.anderson@oracle.com>
Cc: Dan Duval <dan.duval@oracle.com>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE

audit_log_start() does wait_for_auditd() in a loop until
audit_backlog_wait_time passes or audit_skb_queue has a room.

If signal_pending() is true this becomes a busy-wait loop, schedule() in
TASK_INTERRUPTIBLE won't block.

Thanks to Guy for fully investigating and explaining the problem.

(akpm: that'll cause the system to lock up on a non-preemptible
uniprocessor kernel)

(Guy: "Our customer was in fact running a uniprocessor machine, and they
reported a system hang.")

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Guy Streeter <streeter@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

audit: fix message spacing printing auid

The helper function didn't include a leading space, so it was jammed
against the previous text in the audit record.

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

Revert "audit: move kaudit thread start from auditd registration to kaudit init"

This reverts commit 6ff5e45985c2fcb97947818f66d1eeaf9d6600b2.

Conflicts:
kernel/audit.c

This patch was starting a kthread for all the time. Since the follow on
patches that required it didn't get finished in 3.10 time, we shouldn't
ship this change in 3.10.

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

audit: fix event coverage of AUDIT_ANOM_LINK

The userspace audit tools didn't like the existing formatting of the
AUDIT_ANOM_LINK event. It needed to be expanded to emit an AUDIT_PATH
event as well, so this implements the change. The bulk of the patch is
moving code out of auditsc.c into audit.c and audit.h for general use.
It expands audit_log_name to include an optional "struct path" argument
for the simple case of just needing to report a pathname. This also
makes
audit_log_task_info available when syscall auditing is not enabled,
since
it is needed in either case for process details.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Steve Grubb <sgrubb@redhat.com>

audit: use spin_lock in audit_receive_msg to process tty logging

This function is called when we receive a netlink message from
userspace. We don't need to worry about it coming from irq context or
irqs making it re-entrant.

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

audit: add an option to control logging of passwords with pam_tty_audit

Most commands are entered one line at a time and processed as complete lines
in non-canonical mode. Commands that interactively require a password, enter
canonical mode to do this while shutting off echo. This pair of features
(icanon and !echo) can be used to avoid logging passwords by audit while still
logging the rest of the command.

Adding a member (log_passwd) to the struct audit_tty_status passed in by
pam_tty_audit allows control of canonical mode without echo per task.

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

audit: use spin_lock_irqsave/restore in audit tty code

Some of the callers of the audit tty function use spin_lock_irqsave/restore.
We were using the forced always enable version, which seems really bad.
Since I don't know every one of these code paths well enough, it makes
sense to just switch everything to the safe version. Maybe it's a
little overzealous, but it's a lot better than an unlucky deadlock when
we return to a caller with irq enabled and they expect it to be
disabled.

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

helper for some session id stuff

audit: use a consistent audit helper to log lsm information

We have a number of places we were reimplementing the same code to write
out lsm labels. Just do it one darn place.

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

audit: push loginuid and sessionid processing down

Since we are always current, we can push a lot of this stuff to the
bottom and get rid of useless interfaces and arguments.

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

audit: stop pushing loginid, uid, sessionid as arguments

We always use current. Stop pulling this when the skb comes in and
pushing it around as arguments. Just get it at the end when you need
it.

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

audit: remove the old depricated kernel interface

We used to have an inflexible mechanism to add audit rules to the
kernel. It hasn't been used in a long time. Get rid of that stuff.

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

audit: don't check if kauditd is valid every time

We only need to check if kauditd is valid after we start it, if kauditd
is invalid, we will set kauditd_task to NULL. So next time, we will
start kauditd again.

It means if kauditd_task is not NULL,it must be valid.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

audit: allow checking the type of audit message in the user filter

When userspace sends messages to the audit system it includes a type.
We want to be able to filter messages based on that type without have to
do the all or nothing option currently available on the
AUDIT_FILTER_TYPE filter list. Instead we should be able to use the
AUDIT_FILTER_USER filter list and just use the message type as one part
of the matching decision.

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

audit: use data= not msg= for AUDIT_USER_TTY messages

Userspace parsing libraries assume that msg= is only for userspace audit
records, not for user tty records. Make this consistent with the other
tty records.

Reported-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: move kaudit thread start from auditd registration to kaudit init

The kauditd_thread() task was started only after the auditd userspace daemon
registers itself with kaudit. This was fine when only auditd consumed messages
from the kaudit netlink unicast socket. With the addition of a multicast group
to that socket it is more convenient to have the thread start on init of the
kaudit kernel subsystem.

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

audit: flatten kauditd_thread wait queue code

The wait queue control code in kauditd_thread() was nested deeper than
necessary. The function has been flattened for better legibility.

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

audit: refactor hold queue flush

The hold queue flush code is an autonomous chunk of code that can be
refactored, removed from kauditd_thread() into flush_hold_queue() and
flattenned for better legibility.

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

audit: pass int* to nlmsg_next

Commit 941912133025926307c7a65b203fa38403b1063a replaced the macros
NLMSG_NEXT with calls to nlmsg_next which produces this warning:

kernel/audit.c: In function ‘audit_receive_skb’:
kernel/audit.c:928:3: warning: passing argument 2 of ‘nlmsg_next’ makes pointer from integer without a cast
In file included from include/net/rtnetlink.h:5:0,
from include/net/neighbour.h:28,
from include/net/dst.h:17,
from include/net/sock.h:68,
from kernel/audit.c:55:
include/net/netlink.h:359:1: note: expected ‘int *’ but argument is of type ‘int’

Fix this by sending the intended pointer.

Signed-off-by: Alexandru Copot <alex.mihai.c@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: replace obsolete NLMSG_* with type safe nlmsg_*

Signed-off-by: Hong Zhiguo <honkiko@gmail.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/audit.c: avoid negative sleep durations

audit_log_start() performs the same jiffies comparison in two places.
If sufficient time has elapsed between the two comparisons, the second
one produces a negative sleep duration:

schedule_timeout: wrong timeout value fffffffffffffff0
Pid: 6606, comm: trinity-child1 Not tainted 3.8.0-rc1+ #43
Call Trace:
schedule_timeout+0x305/0x340
audit_log_start+0x311/0x470
audit_log_exit+0x4b/0xfb0
__audit_syscall_exit+0x25f/0x2c0
sysret_audit+0x17/0x21

Fix it by performing the comparison a single time.

Reported-by: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

audit: catch possible NULL audit buffers

It's possible for audit_log_start() to return NULL. Handle it in the
various callers.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Julien Tinnes <jln@google.com>
Cc: Will Drewry <wad@google.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs: handle failed audit_log_start properly

audit_log_start() may return NULL, this is unchecked by the caller in
audit_log_link_denied() and could cause a NULL ptr deref.

Introduced by commit a51d9eaa ("fs: add link restriction audit reporting").

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

userns: Convert audit to work with user namespaces enabled

- Explicitly format uids gids in audit messges in the initial user
namespace. This is safe because auditd is restrected to be in
the initial user namespace.

- Convert audit_sig_uid into a kuid_t.

- Enable building the audit code and user namespaces at the same time.

The net result is that the audit subsystem now uses kuid_t and kgid_t whenever
possible making it almost impossible to confuse a raw uid_t with a kuid_t
preventing bugs.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

userns: Convert the audit loginuid to be a kuid

Always store audit loginuids in type kuid_t.

Print loginuids by converting them into uids in the appropriate user
namespace, and then printing the resulting uid.

Modify audit_get_loginuid to return a kuid_t.

Modify audit_set_loginuid to take a kuid_t.

Modify /proc/<pid>/loginuid on read to convert the loginuid into the
user namespace of the opener of the file.

Modify /proc/<pid>/loginud on write to convert the loginuid
rom the user namespace of the opener of the file.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Moore <paul@paul-moore.com> ?
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

audit: Don't pass pid or uid to audit_log_common_recv_msg

The only place we use the uid and the pid that we calculate in
audit_receive_msg is in audit_log_common_recv_msg so move the
calculation of these values into the audit_log_common_recv_msg.

Simplify the calcuation of the current pid and uid by
reading them from current instead of reading them from
NETLINK_CREDS.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

audit: Remove the unused uid parameter from audit_receive_filter

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

audit: Properly set the origin port id of audit messages.

For user generated audit messages set the portid field in the netlink
header to the netlink port where the user generated audit message came
from. Reporting the process id in a port id field was just nonsense.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

audit: Simply AUDIT_TTY_SET and AUDIT_TTY_GET

Use current instead of looking up the current up the current task by
process identifier. Netlink requests are processed in trhe context of
the sending task so this is safe.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

audit: kill audit_prepare_user_tty

Now that netlink messages are processed in the context of the sender
tty_audit_push_task can be called directly and audit_prepare_user_tty
which only added looking up the task of the tty by process id is
not needed.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

audit: Use current instead of NETLINK_CREDS() in audit_filter

Get caller process uid and gid and pid values from the current task
instead of the NETLINK_CB. This is simpler than passing NETLINK_CREDS
from from audit_receive_msg to audit_filter_user_rules and avoid the
chance of being hit by the occassional bugs in netlink uid/gid
credential passing. This is a safe changes because all netlink
requests are processed in the task of the sending process.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

audit: Limit audit requests to processes in the initial pid and user namespaces.

This allows the code to safely make the assumption that all of the
uids gids and pids that need to be send in audit messages are in the
initial namespaces.

If someone cares we may lift this restriction someday but start with
limiting access so at least the code is always correct.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

netlink: Rename pid to portid to avoid confusion

It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.

I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.

I have successfully built an allyesconfig kernel with this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: hide struct module parameter in netlink_kernel_create

This patch defines netlink_kernel_create as a wrapper function of
__netlink_kernel_create to hide the struct module *me parameter
(which seems to be THIS_MODULE in all existing netlink subsystems).

Suggested by David S. Miller.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

fs: add link restriction audit reporting

Adds audit messages for unexpected link restriction violations so that
system owners will have some sort of potentially actionable information
about misbehaving processes.

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

netlink: add netlink_kernel_cfg parameter to netlink_kernel_create

This patch adds the following structure:

struct netlink_kernel_cfg {
unsigned int groups;
void (*input)(struct sk_buff *skb);
struct mutex *cb_mutex;
};

That can be passed to netlink_kernel_create to set optional configurations
for netlink kernel sockets.

I've populated this structure by looking for NULL and zero parameters at the
existing code. The remaining parameters that always need to be set are still
left in the original interface.

That includes optional parameters for the netlink socket creation. This allows
easy extensibility of this interface in the future.

This patch also adapts all callers to use this new interface.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: netlink: Move away from NLMSG_NEW().

And use nlmsg_data() while we're here too.

Signed-off-by: David S. Miller <davem@davemloft.net>

constify path argument of audit_log_d_path()

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

audit: no leading space in audit_log_d_path prefix

audit_log_d_path() injects an additional space before the prefix,
which serves no purpose and doesn't mix well with other audit_log*()
functions that do not sneak extra characters into the log.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric Paris <eparis@redhat.com>

audit: drop the meaningless and format breaking word 'user'

userspace audit messages look like so:

type=USER msg=audit(1271170549.415:24710): user pid=14722 uid=0 auid=500 ses=1 subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 msg=''

That third field just says 'user'. That's useless and doesn't follow the
key=value pair we are trying to enforce. We already know it came from the
user based on the record type. Kill that word. Die.

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

audit: always follow va_copy() with va_end()

A call to va_copy() should always be followed by a call to va_end() in
the same function. In kernel/autit.c::audit_log_vformat() this is not
always done. This patch makes sure va_end() is always called.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security: remove the security_netlink_recv hook as it is equivalent to capable()

Once upon a time netlink was not sync and we had to get the effective
capabilities from the skb that was being received. Today we instead get
the capabilities from the current task. This has rendered the entire
purpose of the hook moot as it is now functionally equivalent to the
capable() call.

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

kernel: Map most files to use export.h instead of module.h

The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else. Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

-#include <linux/module.h>
+#include <linux/export.h>

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

netfilter: add SELinux context support to AUDIT target

In this revision the conversion of secid to SELinux context and adding it
to the audit log is moved from xt_AUDIT.c to audit.c with the aid of a
separate helper function - audit_log_secctx - which does both the conversion
and logging of SELinux context, thus also preventing internal secid number
being leaked to userspace. If conversion is not successful an error is raised.

With the introduction of this helper function the work done in xt_AUDIT.c is
much more simplified. It also opens the possibility of this helper function
being used by other modules (including auditd itself), if desired. With this
addition, typical (raw auditd) output after applying the patch would be:

type=NETFILTER_PKT msg=audit(1305852240.082:31012): action=0 hook=1 len=52 inif=? outif=eth0 saddr=10.1.1.7 daddr=10.1.2.1 ipid=16312 proto=6 sport=56150 dport=22 obj=system_u:object_r:ssh_client_packet_t:s0
type=NETFILTER_PKT msg=audit(1306772064.079:56): action=0 hook=3 len=48 inif=eth0 outif=? smac=00:05:5d:7c:27:0b dmac=00:02:b3:0a:7f:81 macproto=0x0800 saddr=10.1.2.1 daddr=10.1.1.7 ipid=462 proto=6 sport=22 dport=3561 obj=system_u:object_r:ssh_server_packet_t:s0

Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Mr Dash Four <mr.dash.four@googlemail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms

Netlink message processing in the kernel is synchronous these days, the
session information can be collected when needed.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

audit: export symbol for use with xt_AUDIT

When xt_AUDIT is built as a module, modpost reports a problem.

MODPOST 322 modules
ERROR: "audit_enabled" [net/netfilter/x_tables.ko] undefined!
WARNING: modpost: Found 1 section mismatch(es).

Cc: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

audit: error message typo correction

Fixes a typo in the error message raised by audit when auditd has died.

Signed-off-by: Ross Kirk <ross.kirk@nexor.com>

--
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

audit: Use rcu for task lookup protection

Protect the task lookups in audit_receive_msg() with rcu_read_lock()
instead of tasklist_lock and use lock/unlock_sighand to protect
against the exit race.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

audit: Do not send uninitialized data for AUDIT_TTY_GET

audit_receive_msg() sends uninitialized data for AUDIT_TTY_GET when
the task was not found.

Send reply only when task was found.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

audit: Call tty_audit_push_task() outside preempt disabled

While auditing all tasklist_lock read_lock sites I stumbled over the
following call chain:

audit_prepare_user_tty()
read_lock(&tasklist_lock);
tty_audit_push_task();
mutex_lock(&buf->mutex);

--> buf->mutex is locked with preemption disabled.

Solve this by acquiring a reference to the task struct under
rcu_read_lock and call tty_audit_push_task outside of the preempt
disabled region.

Move all code which needs to be protected by sighand lock into
tty_audit_push_task() and use lock/unlock_sighand as we do not hold
tasklist_lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

audit: make functions static

I was doing some namespace checks and found some simple stuff in
audit that could be cleaned up. Make some functions static, and
put const on make_reply payload arg.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Audit: clean up the audit_watch split

No real changes, just cleanup to the audit_watch split patch which we done
with minimal code changes for easy review. Now fix interfaces to make
things work better.

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

drop_monitor: convert some kfree_skb call sites to consume_skb

Convert a few calls from kfree_skb to consume_skb

Noticed while I was working on dropwatch that I was detecting lots of internal
skb drops in several places. While some are legitimate, several were not,
freeing skbs that were at the end of their life, rather than being discarded due
to an error. This patch converts those calls sites from using kfree_skb to
consume_skb, which quiets the in-kernel drop_monitor code from detecting them as
drops. Tested successfully by myself

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Fix misspelling of "should" and "shouldn't" in comments.

Some comments misspell "should" or "shouldn't"; this fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Audit: send signal info if selinux is disabled

Audit will not respond to signal requests if selinux is disabled since it is
unable to translate the 0 sid from the sending process to a context. This
patch just doesn't send the context info if there isn't any.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Fix rule eviction order for AUDIT_DIR

If syscall removes the root of subtree being watched, we
definitely do not want the rules refering that subtree
to be destroyed without the syscall in question having
a chance to match them.

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

Audit: clean up all op= output to include string quoting

A number of places in the audit system we send an op= followed by a string
that includes spaces. Somehow this works but it's just wrong. This patch
moves all of those that I could find to be quoted.

Example:

Change From: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op=remove rule
key="number2" list=4 res=0

Change To: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op="remove rule"
key="number2" list=4 res=0

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

audit: seperate audit inode watches into a subfile

In preparation for converting audit to use fsnotify instead of inotify we
seperate the inode watching code into it's own file. This is similar to
how the audit tree watching code is already seperated into audit_tree.c

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

Audit: clean up audit_receive_skb

audit_receive_skb is hard to clearly parse what it is doing to the netlink
message. Clean the function up so it is easy and clear to see what is going
on.

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

Audit: cleanup netlink mesg handling

The audit handling of netlink messages is all over the place. Clean things
up, use predetermined macros, generally make it more readable.

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

Audit: unify the printk of an skb when auditd not around

Remove code duplication of skb printk when auditd is not around in userspace
to deal with this message.

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

Audit: remove spaces from audit_log_d_path

audit_log_d_path had spaces in the strings which would be emitted on the
error paths. This patch simply replaces those spaces with an _ or removes
the needless spaces entirely.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

audit: ignore terminating NUL in AUDIT_USER_TTY messages

AUDIT_USER_TTY, like all other messages sent from user-space, is sent
NUL-terminated. Unlike other user-space audit messages, which come only
from trusted sources, AUDIT_USER_TTY messages are processed using
audit_log_n_untrustedstring().

This patch modifies AUDIT_USER_TTY handling to ignore the trailing NUL
and use the "quoted_string" representation of the message if possible.

Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Audit: fix handling of 'strings' with NULL characters

currently audit_log_n_untrustedstring() uses audit_string_contains_control()
to check if the 'string' has any control characters. If the 'string' has an
embedded NULL audit_string_contains_control() will return that the data has
no control characters and will then pass the string to audit_log_n_string
with the total length, not the length up to the first NULL.
audit_log_n_string() does a memcpy of the entire length and so the actual
audit record emitted may then contain a NULL and then whatever random memory
is after the NULL.

Since we want to log the entire octet stream (if we can't trust the data
to be a string we can't trust that a NULL isn't actually a part of it)
we should just consider NULL as a control character. If the caller is
certain they want to stop at the first NULL they should be using
audit_log_untrustedstring.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[PATCH] fix broken timestamps in AVC generated by kernel threads

Timestamp in audit_context is valid only if ->in_syscall is set.

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

[PATCH] Audit: make audit=0 actually turn off audit

Currently audit=0 on the kernel command line does absolutely nothing.
Audit always loads and always uses its resources such as creating the
kernel netlink socket. This patch causes audit=0 to actually disable
audit. Audit will use no resources and starting the userspace auditd
daemon will not cause the kernel audit system to activate.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>