<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/auditsc.c, branch v6.1.174</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>audit,io_uring: io_uring openat triggers audit reference count underflow</title>
<updated>2023-10-25T10:03:04+00:00</updated>
<author>
<name>Dan Clash</name>
<email>daclash@linux.microsoft.com</email>
</author>
<published>2023-10-12T21:55:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f7e65c03d5bff682b9266b37345b861a808024cb'/>
<id>f7e65c03d5bff682b9266b37345b861a808024cb</id>
<content type='text'>
commit 03adc61edad49e1bbecfb53f7ea5d78f398fe368 upstream.

An io_uring openat operation can update an audit reference count
from multiple threads resulting in the call trace below.

A call to io_uring_submit() with a single openat op with a flag of
IOSQE_ASYNC results in the following reference count updates.

These first part of the system call performs two increments that do not race.

do_syscall_64()
  __do_sys_io_uring_enter()
    io_submit_sqes()
      io_openat_prep()
        __io_openat_prep()
          getname()
            getname_flags()       /* update 1 (increment) */
              __audit_getname()   /* update 2 (increment) */

The openat op is queued to an io_uring worker thread which starts the
opportunity for a race.  The system call exit performs one decrement.

do_syscall_64()
  syscall_exit_to_user_mode()
    syscall_exit_to_user_mode_prepare()
      __audit_syscall_exit()
        audit_reset_context()
           putname()              /* update 3 (decrement) */

The io_uring worker thread performs one increment and two decrements.
These updates can race with the system call decrement.

io_wqe_worker()
  io_worker_handle_work()
    io_wq_submit_work()
      io_issue_sqe()
        io_openat()
          io_openat2()
            do_filp_open()
              path_openat()
                __audit_inode()   /* update 4 (increment) */
            putname()             /* update 5 (decrement) */
        __audit_uring_exit()
          audit_reset_context()
            putname()             /* update 6 (decrement) */

The fix is to change the refcnt member of struct audit_names
from int to atomic_t.

kernel BUG at fs/namei.c:262!
Call Trace:
...
 ? putname+0x68/0x70
 audit_reset_context.part.0.constprop.0+0xe1/0x300
 __audit_uring_exit+0xda/0x1c0
 io_issue_sqe+0x1f3/0x450
 ? lock_timer_base+0x3b/0xd0
 io_wq_submit_work+0x8d/0x2b0
 ? __try_to_del_timer_sync+0x67/0xa0
 io_worker_handle_work+0x17c/0x2b0
 io_wqe_worker+0x10a/0x350

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/MW2PR2101MB1033FFF044A258F84AEAA584F1C9A@MW2PR2101MB1033.namprd21.prod.outlook.com/
Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Signed-off-by: Dan Clash &lt;daclash@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20231012215518.GA4048@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Reviewed-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 03adc61edad49e1bbecfb53f7ea5d78f398fe368 upstream.

An io_uring openat operation can update an audit reference count
from multiple threads resulting in the call trace below.

A call to io_uring_submit() with a single openat op with a flag of
IOSQE_ASYNC results in the following reference count updates.

These first part of the system call performs two increments that do not race.

do_syscall_64()
  __do_sys_io_uring_enter()
    io_submit_sqes()
      io_openat_prep()
        __io_openat_prep()
          getname()
            getname_flags()       /* update 1 (increment) */
              __audit_getname()   /* update 2 (increment) */

The openat op is queued to an io_uring worker thread which starts the
opportunity for a race.  The system call exit performs one decrement.

do_syscall_64()
  syscall_exit_to_user_mode()
    syscall_exit_to_user_mode_prepare()
      __audit_syscall_exit()
        audit_reset_context()
           putname()              /* update 3 (decrement) */

The io_uring worker thread performs one increment and two decrements.
These updates can race with the system call decrement.

io_wqe_worker()
  io_worker_handle_work()
    io_wq_submit_work()
      io_issue_sqe()
        io_openat()
          io_openat2()
            do_filp_open()
              path_openat()
                __audit_inode()   /* update 4 (increment) */
            putname()             /* update 5 (decrement) */
        __audit_uring_exit()
          audit_reset_context()
            putname()             /* update 6 (decrement) */

The fix is to change the refcnt member of struct audit_names
from int to atomic_t.

kernel BUG at fs/namei.c:262!
Call Trace:
...
 ? putname+0x68/0x70
 audit_reset_context.part.0.constprop.0+0xe1/0x300
 __audit_uring_exit+0xda/0x1c0
 io_issue_sqe+0x1f3/0x450
 ? lock_timer_base+0x3b/0xd0
 io_wq_submit_work+0x8d/0x2b0
 ? __try_to_del_timer_sync+0x67/0xa0
 io_worker_handle_work+0x17c/0x2b0
 io_wqe_worker+0x10a/0x350

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/MW2PR2101MB1033FFF044A258F84AEAA584F1C9A@MW2PR2101MB1033.namprd21.prod.outlook.com/
Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Signed-off-by: Dan Clash &lt;daclash@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20231012215518.GA4048@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Reviewed-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: fix possible soft lockup in __audit_inode_child()</title>
<updated>2023-09-13T07:42:42+00:00</updated>
<author>
<name>Gaosheng Cui</name>
<email>cuigaosheng1@huawei.com</email>
</author>
<published>2023-08-08T12:14:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9ca08adb75fb40a8f742c371927ee73f9dc753bf'/>
<id>9ca08adb75fb40a8f742c371927ee73f9dc753bf</id>
<content type='text'>
[ Upstream commit b59bc6e37237e37eadf50cd5de369e913f524463 ]

Tracefs or debugfs maybe cause hundreds to thousands of PATH records,
too many PATH records maybe cause soft lockup.

For example:
  1. CONFIG_KASAN=y &amp;&amp; CONFIG_PREEMPTION=n
  2. auditctl -a exit,always -S open -k key
  3. sysctl -w kernel.watchdog_thresh=5
  4. mkdir /sys/kernel/debug/tracing/instances/test

There may be a soft lockup as follows:
  watchdog: BUG: soft lockup - CPU#45 stuck for 7s! [mkdir:15498]
  Kernel panic - not syncing: softlockup: hung tasks
  Call trace:
   dump_backtrace+0x0/0x30c
   show_stack+0x20/0x30
   dump_stack+0x11c/0x174
   panic+0x27c/0x494
   watchdog_timer_fn+0x2bc/0x390
   __run_hrtimer+0x148/0x4fc
   __hrtimer_run_queues+0x154/0x210
   hrtimer_interrupt+0x2c4/0x760
   arch_timer_handler_phys+0x48/0x60
   handle_percpu_devid_irq+0xe0/0x340
   __handle_domain_irq+0xbc/0x130
   gic_handle_irq+0x78/0x460
   el1_irq+0xb8/0x140
   __audit_inode_child+0x240/0x7bc
   tracefs_create_file+0x1b8/0x2a0
   trace_create_file+0x18/0x50
   event_create_dir+0x204/0x30c
   __trace_add_new_event+0xac/0x100
   event_trace_add_tracer+0xa0/0x130
   trace_array_create_dir+0x60/0x140
   trace_array_create+0x1e0/0x370
   instance_mkdir+0x90/0xd0
   tracefs_syscall_mkdir+0x68/0xa0
   vfs_mkdir+0x21c/0x34c
   do_mkdirat+0x1b4/0x1d4
   __arm64_sys_mkdirat+0x4c/0x60
   el0_svc_common.constprop.0+0xa8/0x240
   do_el0_svc+0x8c/0xc0
   el0_svc+0x20/0x30
   el0_sync_handler+0xb0/0xb4
   el0_sync+0x160/0x180

Therefore, we add cond_resched() to __audit_inode_child() to fix it.

Fixes: 5195d8e217a7 ("audit: dynamically allocate audit_names when not enough space is in the names array")
Signed-off-by: Gaosheng Cui &lt;cuigaosheng1@huawei.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b59bc6e37237e37eadf50cd5de369e913f524463 ]

Tracefs or debugfs maybe cause hundreds to thousands of PATH records,
too many PATH records maybe cause soft lockup.

For example:
  1. CONFIG_KASAN=y &amp;&amp; CONFIG_PREEMPTION=n
  2. auditctl -a exit,always -S open -k key
  3. sysctl -w kernel.watchdog_thresh=5
  4. mkdir /sys/kernel/debug/tracing/instances/test

There may be a soft lockup as follows:
  watchdog: BUG: soft lockup - CPU#45 stuck for 7s! [mkdir:15498]
  Kernel panic - not syncing: softlockup: hung tasks
  Call trace:
   dump_backtrace+0x0/0x30c
   show_stack+0x20/0x30
   dump_stack+0x11c/0x174
   panic+0x27c/0x494
   watchdog_timer_fn+0x2bc/0x390
   __run_hrtimer+0x148/0x4fc
   __hrtimer_run_queues+0x154/0x210
   hrtimer_interrupt+0x2c4/0x760
   arch_timer_handler_phys+0x48/0x60
   handle_percpu_devid_irq+0xe0/0x340
   __handle_domain_irq+0xbc/0x130
   gic_handle_irq+0x78/0x460
   el1_irq+0xb8/0x140
   __audit_inode_child+0x240/0x7bc
   tracefs_create_file+0x1b8/0x2a0
   trace_create_file+0x18/0x50
   event_create_dir+0x204/0x30c
   __trace_add_new_event+0xac/0x100
   event_trace_add_tracer+0xa0/0x130
   trace_array_create_dir+0x60/0x140
   trace_array_create+0x1e0/0x370
   instance_mkdir+0x90/0xd0
   tracefs_syscall_mkdir+0x68/0xa0
   vfs_mkdir+0x21c/0x34c
   do_mkdirat+0x1b4/0x1d4
   __arm64_sys_mkdirat+0x4c/0x60
   el0_svc_common.constprop.0+0xa8/0x240
   do_el0_svc+0x8c/0xc0
   el0_svc+0x20/0x30
   el0_sync_handler+0xb0/0xb4
   el0_sync+0x160/0x180

Therefore, we add cond_resched() to __audit_inode_child() to fix it.

Fixes: 5195d8e217a7 ("audit: dynamically allocate audit_names when not enough space is in the names array")
Signed-off-by: Gaosheng Cui &lt;cuigaosheng1@huawei.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'audit-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit</title>
<updated>2022-10-04T18:05:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-10-04T18:05:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c645c11a2dba116bad3ee43e08e330db8f03ede6'/>
<id>c645c11a2dba116bad3ee43e08e330db8f03ede6</id>
<content type='text'>
Pull audit updates from Paul Moore:
 "Six audit patches for v6.1, most are pretty trivial, but a quick list
  of the highlights are below:

   - Only free the audit proctitle information on task exit. This allows
     us to cache the information and improve performance slightly.

   - Use the time_after() macro to do time comparisons instead of doing
     it directly and potentially causing ourselves problems when the
     timer wraps.

   - Convert an audit_context state comparison from a relative enum
     comparison, e.g. (x &lt; y), to a not-equal comparison to ensure that
     we are not caught out at some unknown point in the future by an
     enum shuffle.

   - A handful of small cleanups such as tidying up comments and
     removing unused declarations"

* tag 'audit-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: remove selinux_audit_rule_update() declaration
  audit: use time_after to compare time
  audit: free audit_proctitle only on task exit
  audit: explicitly check audit_context-&gt;context enum value
  audit: audit_context pid unused, context enum comment fix
  audit: fix repeated words in comments
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull audit updates from Paul Moore:
 "Six audit patches for v6.1, most are pretty trivial, but a quick list
  of the highlights are below:

   - Only free the audit proctitle information on task exit. This allows
     us to cache the information and improve performance slightly.

   - Use the time_after() macro to do time comparisons instead of doing
     it directly and potentially causing ourselves problems when the
     timer wraps.

   - Convert an audit_context state comparison from a relative enum
     comparison, e.g. (x &lt; y), to a not-equal comparison to ensure that
     we are not caught out at some unknown point in the future by an
     enum shuffle.

   - A handful of small cleanups such as tidying up comments and
     removing unused declarations"

* tag 'audit-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: remove selinux_audit_rule_update() declaration
  audit: use time_after to compare time
  audit: free audit_proctitle only on task exit
  audit: explicitly check audit_context-&gt;context enum value
  audit: audit_context pid unused, context enum comment fix
  audit: fix repeated words in comments
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: free audit_proctitle only on task exit</title>
<updated>2022-08-26T21:18:54+00:00</updated>
<author>
<name>Richard Guy Briggs</name>
<email>rgb@redhat.com</email>
</author>
<published>2022-08-25T19:32:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c3f3ea8af44d0c5fba79fe8b198087342d0c7e04'/>
<id>c3f3ea8af44d0c5fba79fe8b198087342d0c7e04</id>
<content type='text'>
Since audit_proctitle is generated at syscall exit time, its value is
used immediately and cached for the next syscall.  Since this is the
case, then only clear it at task exit time.  Otherwise, there is no
point in caching the value OR bearing the overhead of regenerating it.

Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since audit_proctitle is generated at syscall exit time, its value is
used immediately and cached for the next syscall.  Since this is the
case, then only clear it at task exit time.  Otherwise, there is no
point in caching the value OR bearing the overhead of regenerating it.

Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: explicitly check audit_context-&gt;context enum value</title>
<updated>2022-08-26T21:17:11+00:00</updated>
<author>
<name>Richard Guy Briggs</name>
<email>rgb@redhat.com</email>
</author>
<published>2022-08-25T19:32:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3ed66951f952ed8f1a5d03e171722bf2631e8d58'/>
<id>3ed66951f952ed8f1a5d03e171722bf2631e8d58</id>
<content type='text'>
Be explicit in checking the struct audit_context "context" member enum
value rather than assuming the order of context enum values.

Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Be explicit in checking the struct audit_context "context" member enum
value rather than assuming the order of context enum values.

Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: audit_context pid unused, context enum comment fix</title>
<updated>2022-08-26T21:06:00+00:00</updated>
<author>
<name>Richard Guy Briggs</name>
<email>rgb@redhat.com</email>
</author>
<published>2022-08-25T19:32:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e84d9f5214cb854fcd584aa78b5634794604d306'/>
<id>e84d9f5214cb854fcd584aa78b5634794604d306</id>
<content type='text'>
The pid member of struct audit_context is never used.  Remove it.

The audit_reset_context() comment about unconditionally resetting
"ctx-&gt;state" should read "ctx-&gt;context".

Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The pid member of struct audit_context is never used.  Remove it.

The audit_reset_context() comment about unconditionally resetting
"ctx-&gt;state" should read "ctx-&gt;context".

Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: move audit_return_fixup before the filters</title>
<updated>2022-08-25T21:25:08+00:00</updated>
<author>
<name>Richard Guy Briggs</name>
<email>rgb@redhat.com</email>
</author>
<published>2022-08-25T19:32:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d4fefa4801a1c2f9c0c7a48fbb0fdf384e89a4ab'/>
<id>d4fefa4801a1c2f9c0c7a48fbb0fdf384e89a4ab</id>
<content type='text'>
The success and return_code are needed by the filters.  Move
audit_return_fixup() before the filters.  This was causing syscall
auditing events to be missed.

Link: https://github.com/linux-audit/audit-kernel/issues/138
Cc: stable@vger.kernel.org
Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
[PM: manual merge required]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The success and return_code are needed by the filters.  Move
audit_return_fixup() before the filters.  This was causing syscall
auditing events to be missed.

Link: https://github.com/linux-audit/audit-kernel/issues/138
Cc: stable@vger.kernel.org
Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Richard Guy Briggs &lt;rgb@redhat.com&gt;
[PM: manual merge required]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: fix repeated words in comments</title>
<updated>2022-08-16T02:46:09+00:00</updated>
<author>
<name>Jilin Yuan</name>
<email>yuanjilin@cdjrlc.com</email>
</author>
<published>2022-08-14T09:39:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0351dc57b95b8b56f2a467122c13b6b16e0dc53f'/>
<id>0351dc57b95b8b56f2a467122c13b6b16e0dc53f</id>
<content type='text'>
Delete the redundant word 'doesn't'.

Signed-off-by: Jilin Yuan &lt;yuanjilin@cdjrlc.com&gt;
[PM: subject line tweak]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Delete the redundant word 'doesn't'.

Signed-off-by: Jilin Yuan &lt;yuanjilin@cdjrlc.com&gt;
[PM: subject line tweak]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit, io_uring, io-wq: Fix memory leak in io_sq_thread() and io_wqe_worker()</title>
<updated>2022-08-04T14:33:54+00:00</updated>
<author>
<name>Peilin Ye</name>
<email>peilin.ye@bytedance.com</email>
</author>
<published>2022-08-03T22:23:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f482aa98652795846cc55da98ebe331eb74f3d0b'/>
<id>f482aa98652795846cc55da98ebe331eb74f3d0b</id>
<content type='text'>
Currently @audit_context is allocated twice for io_uring workers:

  1. copy_process() calls audit_alloc();
  2. io_sq_thread() or io_wqe_worker() calls audit_alloc_kernel() (which
     is effectively audit_alloc()) and overwrites @audit_context,
     causing:

  BUG: memory leak
  unreferenced object 0xffff888144547400 (size 1024):
&lt;...&gt;
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [&lt;ffffffff8135cfc3&gt;] audit_alloc+0x133/0x210
      [&lt;ffffffff81239e63&gt;] copy_process+0xcd3/0x2340
      [&lt;ffffffff8123b5f3&gt;] create_io_thread+0x63/0x90
      [&lt;ffffffff81686604&gt;] create_io_worker+0xb4/0x230
      [&lt;ffffffff81686f68&gt;] io_wqe_enqueue+0x248/0x3b0
      [&lt;ffffffff8167663a&gt;] io_queue_iowq+0xba/0x200
      [&lt;ffffffff816768b3&gt;] io_queue_async+0x113/0x180
      [&lt;ffffffff816840df&gt;] io_req_task_submit+0x18f/0x1a0
      [&lt;ffffffff816841cd&gt;] io_apoll_task_func+0xdd/0x120
      [&lt;ffffffff8167d49f&gt;] tctx_task_work+0x11f/0x570
      [&lt;ffffffff81272c4e&gt;] task_work_run+0x7e/0xc0
      [&lt;ffffffff8125a688&gt;] get_signal+0xc18/0xf10
      [&lt;ffffffff8111645b&gt;] arch_do_signal_or_restart+0x2b/0x730
      [&lt;ffffffff812ea44e&gt;] exit_to_user_mode_prepare+0x5e/0x180
      [&lt;ffffffff844ae1b2&gt;] syscall_exit_to_user_mode+0x12/0x20
      [&lt;ffffffff844a7e80&gt;] do_syscall_64+0x40/0x80

Then,

  3. io_sq_thread() or io_wqe_worker() frees @audit_context using
     audit_free();
  4. do_exit() eventually calls audit_free() again, which is okay
     because audit_free() does a NULL check.

As suggested by Paul Moore, fix it by deleting audit_alloc_kernel() and
redundant audit_free() calls.

Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Suggested-by: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Peilin Ye &lt;peilin.ye@bytedance.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Link: https://lore.kernel.org/r/20220803222343.31673-1-yepeilin.cs@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently @audit_context is allocated twice for io_uring workers:

  1. copy_process() calls audit_alloc();
  2. io_sq_thread() or io_wqe_worker() calls audit_alloc_kernel() (which
     is effectively audit_alloc()) and overwrites @audit_context,
     causing:

  BUG: memory leak
  unreferenced object 0xffff888144547400 (size 1024):
&lt;...&gt;
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [&lt;ffffffff8135cfc3&gt;] audit_alloc+0x133/0x210
      [&lt;ffffffff81239e63&gt;] copy_process+0xcd3/0x2340
      [&lt;ffffffff8123b5f3&gt;] create_io_thread+0x63/0x90
      [&lt;ffffffff81686604&gt;] create_io_worker+0xb4/0x230
      [&lt;ffffffff81686f68&gt;] io_wqe_enqueue+0x248/0x3b0
      [&lt;ffffffff8167663a&gt;] io_queue_iowq+0xba/0x200
      [&lt;ffffffff816768b3&gt;] io_queue_async+0x113/0x180
      [&lt;ffffffff816840df&gt;] io_req_task_submit+0x18f/0x1a0
      [&lt;ffffffff816841cd&gt;] io_apoll_task_func+0xdd/0x120
      [&lt;ffffffff8167d49f&gt;] tctx_task_work+0x11f/0x570
      [&lt;ffffffff81272c4e&gt;] task_work_run+0x7e/0xc0
      [&lt;ffffffff8125a688&gt;] get_signal+0xc18/0xf10
      [&lt;ffffffff8111645b&gt;] arch_do_signal_or_restart+0x2b/0x730
      [&lt;ffffffff812ea44e&gt;] exit_to_user_mode_prepare+0x5e/0x180
      [&lt;ffffffff844ae1b2&gt;] syscall_exit_to_user_mode+0x12/0x20
      [&lt;ffffffff844a7e80&gt;] do_syscall_64+0x40/0x80

Then,

  3. io_sq_thread() or io_wqe_worker() frees @audit_context using
     audit_free();
  4. do_exit() eventually calls audit_free() again, which is okay
     because audit_free() does a NULL check.

As suggested by Paul Moore, fix it by deleting audit_alloc_kernel() and
redundant audit_free() calls.

Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Suggested-by: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Peilin Ye &lt;peilin.ye@bytedance.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Link: https://lore.kernel.org/r/20220803222343.31673-1-yepeilin.cs@gmail.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>audit: free module name</title>
<updated>2022-06-15T23:28:44+00:00</updated>
<author>
<name>Christian Göttsche</name>
<email>cgzones@googlemail.com</email>
</author>
<published>2022-06-15T15:44:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ef79c396c664be99d0c5660dc75fe863c1e20315'/>
<id>ef79c396c664be99d0c5660dc75fe863c1e20315</id>
<content type='text'>
Reset the type of the record last as the helper `audit_free_module()`
depends on it.

    unreferenced object 0xffff888153b707f0 (size 16):
      comm "modprobe", pid 1319, jiffies 4295110033 (age 1083.016s)
      hex dump (first 16 bytes):
        62 69 6e 66 6d 74 5f 6d 69 73 63 00 6b 6b 6b a5  binfmt_misc.kkk.
      backtrace:
        [&lt;ffffffffa07dbf9b&gt;] kstrdup+0x2b/0x50
        [&lt;ffffffffa04b0a9d&gt;] __audit_log_kern_module+0x4d/0xf0
        [&lt;ffffffffa03b6664&gt;] load_module+0x9d4/0x2e10
        [&lt;ffffffffa03b8f44&gt;] __do_sys_finit_module+0x114/0x1b0
        [&lt;ffffffffa1f47124&gt;] do_syscall_64+0x34/0x80
        [&lt;ffffffffa200007e&gt;] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Cc: stable@vger.kernel.org
Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Christian Göttsche &lt;cgzones@googlemail.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Reset the type of the record last as the helper `audit_free_module()`
depends on it.

    unreferenced object 0xffff888153b707f0 (size 16):
      comm "modprobe", pid 1319, jiffies 4295110033 (age 1083.016s)
      hex dump (first 16 bytes):
        62 69 6e 66 6d 74 5f 6d 69 73 63 00 6b 6b 6b a5  binfmt_misc.kkk.
      backtrace:
        [&lt;ffffffffa07dbf9b&gt;] kstrdup+0x2b/0x50
        [&lt;ffffffffa04b0a9d&gt;] __audit_log_kern_module+0x4d/0xf0
        [&lt;ffffffffa03b6664&gt;] load_module+0x9d4/0x2e10
        [&lt;ffffffffa03b8f44&gt;] __do_sys_finit_module+0x114/0x1b0
        [&lt;ffffffffa1f47124&gt;] do_syscall_64+0x34/0x80
        [&lt;ffffffffa200007e&gt;] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Cc: stable@vger.kernel.org
Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Christian Göttsche &lt;cgzones@googlemail.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
