All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+a24c397a29ad22d86c98@syzkaller.appspotmail.com>
To: acme@kernel.org, alexander.shishkin@linux.intel.com,
	dvyukov@google.com, jolsa@redhat.com,
	linux-kernel@vger.kernel.org, mingo@redhat.com,
	namhyung@kernel.org, peterz@infradead.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: KASAN: use-after-free Write in _free_event
Date: Mon, 09 Jul 2018 19:16:01 -0700	[thread overview]
Message-ID: <00000000000028fe5e05709bb662@google.com> (raw)
In-Reply-To: <000000000000ccdf0605708a9ccc@google.com>

syzbot has found a reproducer for the following crash on:

HEAD commit:    092150a25cb7 Merge branch 'for-linus' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16627cc2400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=25856fac4e580aa7
dashboard link: https://syzkaller.appspot.com/bug?extid=a24c397a29ad22d86c98
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=14d45afc400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16dd4968400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a24c397a29ad22d86c98@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in atomic_dec_and_test  
include/asm-generic/atomic-instrumented.h:222 [inline]
BUG: KASAN: use-after-free in put_task_struct include/linux/sched/task.h:95  
[inline]
BUG: KASAN: use-after-free in _free_event+0x48d/0x1440  
kernel/events/core.c:4451
Write of size 4 at addr ffff8801ab6360e0 by task syz-executor205/5237

CPU: 1 PID: 5237 Comm: syz-executor205 Not tainted 4.18.0-rc4+ #139
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
  print_address_description+0x6c/0x20b mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
  check_memory_region_inline mm/kasan/kasan.c:260 [inline]
  check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
  kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
  atomic_dec_and_test include/asm-generic/atomic-instrumented.h:222 [inline]
  put_task_struct include/linux/sched/task.h:95 [inline]
  _free_event+0x48d/0x1440 kernel/events/core.c:4451
  free_event+0xb4/0x180 kernel/events/core.c:4472
  perf_event_release_kernel+0x7d5/0x1050 kernel/events/core.c:4633
  perf_release+0x37/0x50 kernel/events/core.c:4647
  __fput+0x355/0x8b0 fs/file_table.c:209
  ____fput+0x15/0x20 fs/file_table.c:243
  task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
  exit_task_work include/linux/task_work.h:22 [inline]
  do_exit+0x1b08/0x2750 kernel/exit.c:865
  do_group_exit+0x177/0x440 kernel/exit.c:968
  get_signal+0x88e/0x1970 kernel/signal.c:2468
  do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816
  exit_to_usermode_loop+0x2e0/0x370 arch/x86/entry/common.c:162
  prepare_exit_to_usermode+0x342/0x3b0 arch/x86/entry/common.c:197
  retint_user+0x8/0x18
RIP: 0033:          (null)
Code: Bad RIP value.
RSP: 002b:0000000020000048 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00000000006dbc24 RCX: 0000000000445d89
RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000020000080 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000006dbc20
R13: 0030656c69662f2e R14: 0000004000008912 R15: 0000000000000006

Allocated by task 5236:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
  kmem_cache_alloc_node+0x144/0x780 mm/slab.c:3644
  alloc_task_struct_node kernel/fork.c:157 [inline]
  dup_task_struct kernel/fork.c:779 [inline]
  copy_process.part.39+0x16b5/0x7220 kernel/fork.c:1641
  copy_process kernel/fork.c:1616 [inline]
  _do_fork+0x291/0x12a0 kernel/fork.c:2099
  __do_sys_clone kernel/fork.c:2206 [inline]
  __se_sys_clone kernel/fork.c:2200 [inline]
  __x64_sys_clone+0xbf/0x150 kernel/fork.c:2200
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 5236:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:448
  set_track mm/kasan/kasan.c:460 [inline]
  __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
  kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
  __cache_free mm/slab.c:3498 [inline]
  kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
  free_task_struct kernel/fork.c:162 [inline]
  free_task+0x16e/0x1f0 kernel/fork.c:390
  copy_process.part.39+0x15c9/0x7220 kernel/fork.c:2034
  copy_process kernel/fork.c:1616 [inline]
  _do_fork+0x291/0x12a0 kernel/fork.c:2099
  __do_sys_clone kernel/fork.c:2206 [inline]
  __se_sys_clone kernel/fork.c:2200 [inline]
  __x64_sys_clone+0xbf/0x150 kernel/fork.c:2200
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801ab6360c0
  which belongs to the cache task_struct of size 5952
The buggy address is located 32 bytes inside of
  5952-byte region [ffff8801ab6360c0, ffff8801ab637800)
The buggy address belongs to the page:
page:ffffea0006ad8d80 count:1 mapcount:0 mapping:ffff8801da94b200 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006ad9008 ffffea00075f5888 ffff8801da94b200
raw: 0000000000000000 ffff8801ab6360c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801ab635f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff8801ab636000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8801ab636080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                        ^
  ffff8801ab636100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801ab636180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


      parent reply	other threads:[~2018-07-10  2:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-09  5:52 KASAN: use-after-free Write in _free_event syzbot
2018-07-09 10:11 ` Alexander Shishkin
2018-07-09 11:02   ` Dmitry Vyukov
2019-02-16 10:43   ` Xie XiuQi
2019-02-28 14:01     ` [RFC PATCH] perf: Paper over the hw.target problems Alexander Shishkin
     [not found]       ` <c174549c-d169-7773-2f47-5863ba0b8056@huawei.com>
2019-03-08 12:38         ` Alexander Shishkin
2019-03-11 13:32           ` chengjian (D)
2019-03-08 15:54       ` Mark Rutland
2019-06-24 12:19         ` Peter Zijlstra
2019-06-25  8:49           ` Peter Zijlstra
2019-06-25 10:43             ` [PATCH] perf: Fix race between close() and fork() Peter Zijlstra
2019-06-25 12:20               ` Alexander Shishkin
2019-06-28 16:50               ` Mark Rutland
2019-06-28 20:46                 ` Peter Zijlstra
2019-07-01  9:24                   ` Mark Rutland
2018-07-10  2:16 ` syzbot [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=00000000000028fe5e05709bb662@google.com \
    --to=syzbot+a24c397a29ad22d86c98@syzkaller.appspotmail.com \
    --cc=acme@kernel.org \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=dvyukov@google.com \
    --cc=jolsa@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=namhyung@kernel.org \
    --cc=peterz@infradead.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.