syzbot


KCSAN: data-race in __io_async_wake / futex_wait_queue_me (2)

Status: auto-closed as invalid on 2021/03/21 12:06
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 540d, last: 540d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __io_async_wake / futex_wait_queue_me 3 620d 609d 0/23 auto-closed as invalid on 2020/12/31 20:52

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __io_async_wake / futex_wait_queue_me

write to 0xffff8881350a902c of 4 bytes by task 12375 on cpu 0:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 futex_wait_queue_me+0x1a8/0x250 kernel/futex.c:2606
 futex_wait+0x145/0x3d0 kernel/futex.c:2708
 do_futex+0x105d/0x1cc0 kernel/futex.c:3736
 __do_sys_futex kernel/futex.c:3799 [inline]
 __se_sys_futex+0x2a8/0x390 kernel/futex.c:3765
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3765
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881350a902c of 4 bytes by task 12370 on cpu 1:
 io_req_task_work_add fs/io_uring.c:2155 [inline]
 __io_async_wake+0x18b/0x330 fs/io_uring.c:5160
 io_poll_wake+0x2d/0x40 fs/io_uring.c:5631
 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:108
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x80/0xc0 kernel/sched/wait.c:157
 pipe_release+0x127/0x1e0 fs/pipe.c:712
 __fput+0x24e/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x17c/0x1b0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:294
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12370 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/02/14 12:03 upstream 358feceebbf6 98682e5e .config log report info KCSAN: data-race in __io_async_wake / futex_wait_queue_me