KCSAN: data-race in ktime_get_seconds / timekeeping_advance (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: b12d66a6 mm, kcsan: Instrument SLAB free with ASSERT_EXCLU..
git tree: https://github.com/google/ktsan.git kcsan
console output: https://syzkaller.appspot.com/x/log.txt?x=10434ee6e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=10bc0131c4924ba9
dashboard link: https://syzkaller.appspot.com/bug?extid=2f6ed79eeea833427e15
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [john....@linaro.org linux-...@vger.kernel.org sb...@kernel.org tg...@linutronix.de el...@google.com]

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+2f6ed7...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in ktime_get_seconds / timekeeping_advance

write to 0xffffffff8622f2c8 of 280 bytes by interrupt on cpu 0:
timekeeping_advance+0x88e/0xd80 include/linux/string.h:381
update_wall_time+0x19/0x20 kernel/time/timekeeping.c:2137
tick_do_update_jiffies64+0x1ef/0x2b0 kernel/time/tick-sched.c:98
tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:142
tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1307
__run_hrtimer kernel/time/hrtimer.c:1517 [inline]
__hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1579
hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1641
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1144
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
kcsan_setup_watchpoint+0x22c/0x3e0 kernel/kcsan/core.c:527
check_access kernel/kcsan/core.c:564 [inline]
__tsan_read4+0xc6/0x100 kernel/kcsan/core.c:699
receive_mergeable drivers/net/virtio_net.c:917 [inline]
receive_buf+0x178d/0x30d0 drivers/net/virtio_net.c:1033
virtnet_receive drivers/net/virtio_net.c:1323 [inline]
virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
napi_poll net/core/dev.c:6582 [inline]
net_rx_action+0x3ae/0xa90 net/core/dev.c:6650
__do_softirq+0x115/0x33f kernel/softirq.c:292
run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffffff8622f340 of 8 bytes by task 7960 on cpu 1:
ktime_get_seconds+0x45/0x70 kernel/time/timekeeping.c:917
tcp_store_ts_recent net/ipv4/tcp_input.c:3490 [inline]
tcp_rcv_established+0xeeb/0xf50 net/ipv4/tcp_input.c:5674
tcp_v4_do_rcv+0x3b5/0x520 net/ipv4/tcp_ipv4.c:1619
sk_backlog_rcv include/net/sock.h:938 [inline]
__release_sock+0x135/0x1e0 net/core/sock.c:2437
release_sock+0x61/0x160 net/core/sock.c:2953
tcp_recvmsg+0x68f/0x1cc0 net/ipv4/tcp.c:2185
inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
sock_recvmsg_nosec net/socket.c:886 [inline]
sock_recvmsg net/socket.c:904 [inline]
sock_recvmsg+0x92/0xb0 net/socket.c:900
sock_read_iter+0x17c/0x220 net/socket.c:982
call_read_iter include/linux/fs.h:1895 [inline]
new_sync_read+0x4b1/0x4f0 fs/read_write.c:414
__vfs_read+0xb1/0xc0 fs/read_write.c:427
vfs_read fs/read_write.c:461 [inline]
vfs_read+0x143/0x2c0 fs/read_write.c:446
ksys_read+0x17b/0x1b0 fs/read_write.c:587
__do_sys_read fs/read_write.c:597 [inline]
__se_sys_read fs/read_write.c:595 [inline]
__x64_sys_read+0x4c/0x60 fs/read_write.c:595
do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7960 Comm: syz-fuzzer Not tainted 5.6.0-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.