syzbot


KCSAN: data-race in __fput / ep_remove (2)

Status: auto-closed as invalid on 2022/06/25 02:37
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 224d, last: 196d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __fput / ep_remove 1 583d 583d 0/24 auto-closed as invalid on 2021/06/02 19:47

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __fput / ep_remove

write to 0xffff888149d7fcd0 of 8 bytes by task 1950 on cpu 1:
 ep_remove+0x310/0x360 fs/eventpoll.c:704
 ep_free+0x18b/0x210 fs/eventpoll.c:778
 ep_eventpoll_release+0x2e/0x40 fs/eventpoll.c:795
 __fput+0x292/0x510 fs/file_table.c:317
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 get_signal+0xeca/0x1020 kernel/signal.c:2641
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:867
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888149d7fcd0 of 8 bytes by task 1894 on cpu 0:
 eventpoll_release include/linux/eventpoll.h:45 [inline]
 __fput+0x20b/0x510 fs/file_table.c:308
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 get_signal+0xeca/0x1020 kernel/signal.c:2641
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:867
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff8881049243f0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1894 Comm: syz-executor.1 Not tainted 5.18.0-rc7-syzkaller-00121-g3d7285a335ed-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/21 02:32 upstream 3d7285a335ed bd37ad7e .config log report info KCSAN: data-race in __fput / ep_remove
ci2-upstream-kcsan-gce 2022/04/23 02:43 upstream d569e86915b7 131df97d .config log report info KCSAN: data-race in __fput / ep_remove
* Struck through repros no longer work on HEAD.