KCSAN: data-race in tick_nohz_next_event / tick_sched_do_timer (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 7c3cd68e Merge remote-tracking branch 'linux-rcu/kcsan' in..
git tree: https://github.com/google/ktsan.git kcsan
console output: https://syzkaller.appspot.com/x/log.txt?x=132ea872100000
kernel config: https://syzkaller.appspot.com/x/.config?x=ff291dc25f22cdda
dashboard link: https://syzkaller.appspot.com/bug?extid=461c1960379fc03b4a21
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [fwei...@gmail.com linux-...@vger.kernel.org mi...@kernel.org tg...@linutronix.de]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+461c19...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in tick_nohz_next_event / tick_sched_do_timer

write to 0xffffffff8764e210 of 4 bytes by interrupt on cpu 0:
tick_sched_do_timer+0xb4/0xd0 kernel/time/tick-sched.c:141
tick_sched_timer+0x3f/0xd0 kernel/time/tick-sched.c:1313
__run_hrtimer kernel/time/hrtimer.c:1520 [inline]
__hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1584
hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1646
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline]
smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1138
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
arch_safe_halt arch/x86/include/asm/paravirt.h:144 [inline]
default_idle+0x21/0x170 arch/x86/kernel/process.c:697
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x1b7/0x290 kernel/sched/idle.c:269
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
rest_init+0xe4/0xeb init/main.c:667
arch_call_rest_init+0x13/0x2b
start_kernel+0x7fe/0x823 init/main.c:1005
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

read to 0xffffffff8764e210 of 4 bytes by task 0 on cpu 1:
tick_nohz_next_event+0x181/0x340 kernel/time/tick-sched.c:746
__tick_nohz_idle_stop_tick kernel/time/tick-sched.c:964 [inline]
tick_nohz_idle_stop_tick+0x3b9/0x680 kernel/time/tick-sched.c:994
cpuidle_idle_call kernel/sched/idle.c:151 [inline]
do_idle+0x1ad/0x290 kernel/sched/idle.c:269
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
start_secondary+0x169/0x1b0 arch/x86/kernel/smpboot.c:268
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.