syzbot


WARNING in free_event

Status: auto-obsoleted due to no activity on 2024/11/01 15:54
Subsystems: perf
[Documentation on labels]
First crash: 421d, last: 223d
Cause bisection: introduced by (bisect log) [merge commit]:
commit eea8bebd51739cc7a3bb501032ee877b4aada553
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun Dec 4 20:33:44 2022 +0000

  Merge tag 'timers_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Crash: KFENCE: use-after-free in task_work_run (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 058244c683111d44a5de16ac74f19a1754dd7a0c
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Jul 4 17:03:35 2024 +0000

  perf: Move irq_work_queue() where the event is prepared.

  
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/05/13 23:49 20m retest repro bpf report log
2024/01/08 13:37 14m retest repro bpf report log
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/08/09 07:53 6h41m bisect fix bpf OK (1) job log
2024/07/09 13:32 7h41m bisect fix bpf OK (0) job log log
2024/03/04 22:04 1h28m bisect fix bpf OK (0) job log log

Sample crash report:
------------[ cut here ]------------
unexpected event refcount: 2; ptr=ffff88807c613040
WARNING: CPU: 1 PID: 5449 at kernel/events/core.c:5254 free_event+0xa0/0xc0 kernel/events/core.c:5254
Modules linked in:
CPU: 1 PID: 5449 Comm: syz-executor283 Not tainted 6.7.0-rc6-syzkaller-g7c5e046bdcb2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:free_event+0xa0/0xc0 kernel/events/core.c:5254
Code: b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 24 48 8b b3 38 02 00 00 48 89 da 48 c7 c7 00 f7 d6 8a e8 d1 82 9c ff 90 <0f> 0b 90 90 5b 5d 41 5c e9 13 41 d6 ff 4c 89 e7 e8 4b eb 2c 00 eb
RSP: 0018:ffffc9000481fa00 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88807c613040 RCX: ffffffff814db519
RDX: ffff88802566bb80 RSI: ffffffff814db526 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88807c613278
R13: ffff88802951552c R14: ffff88807c613040 R15: ffff88807c613320
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200000cc CR3: 000000000cd77000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 perf_event_release_kernel+0x5eb/0x8f0 kernel/events/core.c:5421
 perf_release+0x37/0x50 kernel/events/core.c:5442
 __fput+0x270/0xb70 fs/file_table.c:394
 task_work_run+0x14d/0x240 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa8a/0x2ad0 kernel/exit.c:869
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1018
 get_signal+0x23b5/0x2790 kernel/signal.c:2904
 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x121/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/25 12:57 bpf 7c5e046bdcb2 fb427a07 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce WARNING in free_event
* Struck through repros no longer work on HEAD.