KCSAN: data-race in tick_nohz_idle_stop_tick / 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=13dc9eda100000
kernel config: https://syzkaller.appspot.com/x/.config?x=ff291dc25f22cdda
dashboard link: https://syzkaller.appspot.com/bug?extid=8751258c7b05b27b08c9
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+875125...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in tick_nohz_idle_stop_tick / 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
__this_cpu_preempt_check+0x40/0x130 lib/smp_processor_id.c:65
xt_write_recseq_begin include/linux/netfilter/x_tables.h:378 [inline]
ipt_do_table+0x1f6/0xe70 net/ipv4/netfilter/ip_tables.c:260
iptable_raw_hook+0x44/0x60 net/ipv4/netfilter/iptable_raw.c:44
nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
nf_hook_slow+0x7c/0x160 net/netfilter/core.c:512
nf_hook_slow_list+0x140/0x29f net/netfilter/core.c:550
NF_HOOK_LIST include/linux/netfilter.h:343 [inline]
ip_sublist_rcv+0x4f9/0x530 net/ipv4/ip_input.c:606
ip_list_rcv+0x2f3/0x321 net/ipv4/ip_input.c:643
__netif_receive_skb_list_ptype net/core/dev.c:5230 [inline]
__netif_receive_skb_list_ptype net/core/dev.c:5219 [inline]
__netif_receive_skb_list_core+0x368/0x5c0 net/core/dev.c:5278
__netif_receive_skb_list net/core/dev.c:5330 [inline]
netif_receive_skb_list_internal+0x5c7/0x810 net/core/dev.c:5425
gro_normal_list.part.0+0x37/0xa0 net/core/dev.c:5536
gro_normal_list net/core/dev.c:5549 [inline]
gro_normal_one+0x14c/0x160 net/core/dev.c:5548
napi_skb_finish net/core/dev.c:5876 [inline]
napi_gro_receive+0x27d/0x2f0 net/core/dev.c:5908
receive_buf+0x24c/0x3420 drivers/net/virtio_net.c:1073
virtnet_receive drivers/net/virtio_net.c:1335 [inline]
virtnet_poll+0x343/0x790 drivers/net/virtio_net.c:1440
napi_poll net/core/dev.c:6571 [inline]
net_rx_action+0x3ad/0xac0 net/core/dev.c:6639
__do_softirq+0x118/0x34a kernel/softirq.c:292
run_ksoftirqd+0x41/0x60 kernel/softirq.c:604
smpboot_thread_fn+0x374/0x4a0 kernel/smpboot.c:165
kthread+0x203/0x230 kernel/kthread.c:268
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffffff8764e210 of 4 bytes by task 0 on cpu 1:
tick_nohz_stop_tick kernel/time/tick-sched.c:780 [inline]
__tick_nohz_idle_stop_tick kernel/time/tick-sched.c:973 [inline]
tick_nohz_idle_stop_tick+0x191/0x680 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
==================================================================


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[syzbot]

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