syzbot


KCSAN: data-race in __lock_timer / do_timer_create

Status: auto-closed as invalid on 2022/04/22 16:54
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 254d, last: 254d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __lock_timer / do_timer_create (2) 1 187d 187d 0/24 auto-closed as invalid on 2022/06/28 20:27

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __lock_timer / do_timer_create

write to 0xffff888105404f60 of 8 bytes by task 32163 on cpu 0:
 do_timer_create+0x965/0xa80 kernel/time/posix-timers.c:561
 __se_sys_timer_create kernel/time/posix-timers.c:577 [inline]
 __x64_sys_timer_create+0xb7/0xe0 kernel/time/posix-timers.c:577
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888105404f60 of 8 bytes by task 32164 on cpu 1:
 __posix_timers_find kernel/time/posix-timers.c:126 [inline]
 posix_timer_by_id kernel/time/posix-timers.c:137 [inline]
 __lock_timer+0x9c/0x180 kernel/time/posix-timers.c:626
 do_timer_settime+0x103/0x240 kernel/time/posix-timers.c:914
 __do_sys_timer_settime kernel/time/posix-timers.c:952 [inline]
 __se_sys_timer_settime kernel/time/posix-timers.c:938 [inline]
 __x64_sys_timer_settime+0xe4/0x150 kernel/time/posix-timers.c:938
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000000 -> 0xffff8881310d3240

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 32164 Comm: syz-executor.3 Not tainted 5.17.0-rc8-syzkaller-00045-g551acdc3c3d2-dirty #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 2022/03/18 16:45 upstream 551acdc3c3d2 e2d91b1d .config log report info KCSAN: data-race in __lock_timer / do_timer_create
* Struck through repros no longer work on HEAD.