syzbot


KCSAN: data-race in do_timer_create / do_timer_create (3)

Status: auto-closed as invalid on 2021/12/05 03:50
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 398d, last: 393d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_timer_create / do_timer_create 1 566d 566d 0/24 auto-closed as invalid on 2021/06/14 21:07
upstream KCSAN: data-race in do_timer_create / do_timer_create (2) 1 523d 523d 0/24 auto-closed as invalid on 2021/07/28 07:48
upstream KCSAN: data-race in do_timer_create / do_timer_create (6) 1 63d 63d 0/24 auto-obsoleted due to no activity on 2022/10/31 13:32
upstream KCSAN: data-race in do_timer_create / do_timer_create (5) 10 116d 222d 0/24 auto-closed as invalid on 2022/09/07 15:06
upstream KCSAN: data-race in do_timer_create / do_timer_create (4) 18 261d 348d 0/24 auto-closed as invalid on 2022/04/16 01:14

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

write to 0xffff88812d02e5bc of 4 bytes by task 3235 on cpu 1:
 do_timer_create+0x386/0xae0 kernel/time/posix-timers.c:516
 __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+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812d02e5bc of 4 bytes by task 3234 on cpu 0:
 posix_timer_add kernel/time/posix-timers.c:143 [inline]
 do_timer_create+0x1f2/0xae0 kernel/time/posix-timers.c:516
 __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+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000003 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3234 Comm: syz-executor.1 Not tainted 5.15.0-rc7-syzkaller #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 2021/10/31 03:47 upstream 119c85055d86 098b5d53 .config log report info KCSAN: data-race in do_timer_create / do_timer_create
ci2-upstream-kcsan-gce 2021/10/26 10:31 upstream 87066fdd2e30 c1132b49 .config log report info KCSAN: data-race in do_timer_create / do_timer_create
* Struck through repros no longer work on HEAD.