syzbot


KCSAN: data-race in tick_nohz_stop_tick / tick_nohz_stop_tick

Status: auto-closed as invalid on 2020/07/24 20:53
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 892d, last: 892d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in tick_nohz_stop_tick / tick_nohz_stop_tick (2) 507 4h21m 735d 0/24 moderation: reported on 2020/11/23 09:55

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

write to 0xffffffff87f50690 of 4 bytes by task 0 on cpu 0:
 tick_nohz_stop_tick+0xa0/0x440 kernel/time/tick-sched.c:781
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:973 [inline]
 tick_nohz_idle_stop_tick+0xf2/0x1c0 kernel/time/tick-sched.c:994
 cpuidle_idle_call kernel/sched/idle.c:201 [inline]
 do_idle+0x1ac/0x320 kernel/sched/idle.c:269
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:365
 rest_init+0xd8/0xe0 init/main.c:705
 arch_call_rest_init+0xa/0xb
 start_kernel+0x608/0x6d0 init/main.c:1043
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

read to 0xffffffff87f50690 of 4 bytes by task 0 on cpu 1:
 tick_nohz_stop_tick+0x7a/0x440 kernel/time/tick-sched.c:780
 __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:973 [inline]
 tick_nohz_idle_stop_tick+0xf2/0x1c0 kernel/time/tick-sched.c:994
 cpuidle_idle_call kernel/sched/idle.c:201 [inline]
 do_idle+0x1ac/0x320 kernel/sched/idle.c:269
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:365
 start_secondary+0xe3/0x110 arch/x86/kernel/smpboot.c:268
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.8.0-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 2020/06/19 20:50 upstream 672f9255a727 123cf502 .config log report
* Struck through repros no longer work on HEAD.