linux/include
Peilin Ye f482aa9865 audit, io_uring, io-wq: Fix memory leak in io_sq_thread() and io_wqe_worker()
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):
<...>
    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:
      [<ffffffff8135cfc3>] audit_alloc+0x133/0x210
      [<ffffffff81239e63>] copy_process+0xcd3/0x2340
      [<ffffffff8123b5f3>] create_io_thread+0x63/0x90
      [<ffffffff81686604>] create_io_worker+0xb4/0x230
      [<ffffffff81686f68>] io_wqe_enqueue+0x248/0x3b0
      [<ffffffff8167663a>] io_queue_iowq+0xba/0x200
      [<ffffffff816768b3>] io_queue_async+0x113/0x180
      [<ffffffff816840df>] io_req_task_submit+0x18f/0x1a0
      [<ffffffff816841cd>] io_apoll_task_func+0xdd/0x120
      [<ffffffff8167d49f>] tctx_task_work+0x11f/0x570
      [<ffffffff81272c4e>] task_work_run+0x7e/0xc0
      [<ffffffff8125a688>] get_signal+0xc18/0xf10
      [<ffffffff8111645b>] arch_do_signal_or_restart+0x2b/0x730
      [<ffffffff812ea44e>] exit_to_user_mode_prepare+0x5e/0x180
      [<ffffffff844ae1b2>] syscall_exit_to_user_mode+0x12/0x20
      [<ffffffff844a7e80>] 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: 5bd2182d58 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Suggested-by: Paul Moore <paul@paul-moore.com>
Cc: stable@vger.kernel.org
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20220803222343.31673-1-yepeilin.cs@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-04 08:33:54 -06:00
..
acpi Merge branches 'acpi-processor', 'acpi-apei' and 'acpi-ec' 2022-07-29 20:08:25 +02:00
asm-generic Random number generator updates for Linux 6.0-rc1. 2022-08-02 17:31:35 -07:00
clocksource - Add the missing DT bindings for the MTU nomadik timer (Linus 2022-07-28 12:33:34 +02:00
crypto crypto: aria - Implement ARIA symmetric cipher algorithm 2022-07-15 16:38:19 +08:00
drm drm/scheduler: Don't kill jobs in interrupt context 2022-07-15 10:09:15 -04:00
dt-bindings ARM: new SoC support for 6.0 2022-08-02 08:29:18 -07:00
keys certs: Move load_certificate_list() to be with the asymmetric keys code 2022-06-21 16:05:06 +01:00
kunit kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites 2022-07-11 17:13:15 -06:00
kvm
linux audit, io_uring, io-wq: Fix memory leak in io_sq_thread() and io_wqe_worker() 2022-08-04 08:33:54 -06:00
math-emu
media
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net for-5.20/io_uring-2022-07-29 2022-08-02 13:20:44 -07:00
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scsi scsi/core: Use the new blk_opf_t type 2022-07-14 12:14:32 -06:00
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sound ASoC: Remove unused hw_write_t type 2022-06-24 16:21:41 +01:00
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trace for-5.20/block-2022-07-29 2022-08-02 13:46:35 -07:00
uapi flexible-array transformations in UAPI for 6.0-rc1 2022-08-02 19:50:47 -07:00
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video video: of_display_timing.h: include errno.h 2022-07-06 17:16:20 +02:00
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