syzbot


KCSAN: data-race in __lock_timer / __se_sys_timer_delete

Status: auto-closed as invalid on 2021/12/23 00:32
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 384d, last: 384d

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

write to 0xffff88813d4b9960 of 8 bytes by task 13176 on cpu 0:
 __do_sys_timer_delete kernel/time/posix-timers.c:1028 [inline]
 __se_sys_timer_delete+0x1c4/0x2d0 kernel/time/posix-timers.c:1004
 __x64_sys_timer_delete+0x1b/0x20 kernel/time/posix-timers.c:1004
 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 0xffff88813d4b9960 of 8 bytes by task 13174 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: 0xffff88813bcbe000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13174 Comm: syz-executor.3 Tainted: G        W         5.16.0-rc1-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 2021/11/18 00:32 upstream ee1703cda8dc cafff8b6 .config log report info KCSAN: data-race in __lock_timer / __se_sys_timer_delete
* Struck through repros no longer work on HEAD.