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BUG: KCSAN: data-race in internal_add_timer / update_process_times

write to 0xffff888237c376d8 of 8 bytes by interrupt on cpu 1:
 enqueue_timer kernel/time/timer.c:598 [inline]
 internal_add_timer+0x146/0x270 kernel/time/timer.c:611
 add_timer_on+0x262/0x2a0 kernel/time/timer.c:1182
 clocksource_watchdog+0xa74/0xac0 kernel/time/clocksource.c:478
 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1421
 expire_timers+0x135/0x240 kernel/time/timer.c:1466
 __run_timers+0x358/0x420 kernel/time/timer.c:1734
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1747
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu kernel/softirq.c:636 [inline]
 irq_exit_rcu+0x4e/0xa0 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 iovec_from_user+0x2b5/0x2d0 lib/iov_iter.c:1873
 __import_iovec+0x57/0x2c0 lib/iov_iter.c:1887
 import_iovec+0x69/0x80 lib/iov_iter.c:1952
 copy_msghdr_from_user net/socket.c:2333 [inline]
 recvmsg_copy_msghdr net/socket.c:2580 [inline]
 ___sys_recvmsg net/socket.c:2652 [inline]
 do_recvmmsg+0x68b/0x9f0 net/socket.c:2750
 __sys_recvmmsg net/socket.c:2829 [inline]
 __do_sys_recvmmsg net/socket.c:2852 [inline]
 __se_sys_recvmmsg net/socket.c:2845 [inline]
 __x64_sys_recvmmsg+0xcf/0x150 net/socket.c:2845
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237c376d8 of 8 bytes by interrupt on cpu 0:
 run_local_timers kernel/time/timer.c:1761 [inline]
 update_process_times+0x8c/0x150 kernel/time/timer.c:1784
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x191/0x210 kernel/time/tick-sched.c:1421
 __run_hrtimer+0x160/0x480 kernel/time/hrtimer.c:1685
 __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline]
 hrtimer_interrupt+0x380/0xaf0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x1c0 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x64/0x80 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 finish_task_switch+0xda/0x290 kernel/sched/core.c:4814
 context_switch kernel/sched/core.c:4943 [inline]
 __schedule+0x42c/0x670 kernel/sched/core.c:6287
 schedule+0x67/0x90 kernel/sched/core.c:6366
 schedule_timeout+0x42/0x240 kernel/time/timer.c:1857
 unix_wait_for_peer+0x12d/0x1d0 net/unix/af_unix.c:1227
 unix_dgram_sendmsg+0xd0f/0x1600 net/unix/af_unix.c:1816
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg net/socket.c:723 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2395
 ___sys_sendmsg net/socket.c:2449 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2535
 __do_sys_sendmmsg net/socket.c:2564 [inline]
 __se_sys_sendmmsg net/socket.c:2561 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2561
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000ffffc800 -> 0x00000000ffffc72b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9293 Comm: syz-executor.4 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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