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BUG: KCSAN: data-race in internal_add_timer / update_process_times

write to 0xffff888237c176d8 of 8 bytes by interrupt on cpu 1:
 enqueue_timer kernel/time/timer.c:598 [inline]
 internal_add_timer+0x14f/0x280 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+0x368/0x430 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_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline]
 arch_atomic64_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2265 [inline]
 arch_atomic64_add_unless include/linux/atomic/atomic-arch-fallback.h:2290 [inline]
 arch_atomic_long_add_unless include/linux/atomic/atomic-long.h:491 [inline]
 atomic_long_add_unless include/linux/atomic/atomic-instrumented.h:1727 [inline]
 __fget_files fs/file.c:859 [inline]
 __fget fs/file.c:870 [inline]
 __fget_light+0x179/0x260 fs/file.c:965
 __fdget+0x14/0x20 fs/file.c:973
 fdget include/linux/file.h:65 [inline]
 ksys_pwrite64 fs/read_write.c:697 [inline]
 __do_sys_pwrite64 fs/read_write.c:711 [inline]
 __se_sys_pwrite64 fs/read_write.c:708 [inline]
 __x64_sys_pwrite64+0x79/0x150 fs/read_write.c:708
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237c176d8 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
 check_access kernel/kcsan/core.c:631 [inline]
 __tsan_read4+0x108/0x180 kernel/kcsan/core.c:854
 legitimize_path fs/namei.c:708 [inline]
 try_to_unlazy+0x1e9/0x650 fs/namei.c:777
 complete_walk+0xb3/0x1e0 fs/namei.c:883
 path_parentat fs/namei.c:2498 [inline]
 filename_parentat+0x145/0x480 fs/namei.c:2519
 do_unlinkat+0x83/0x540 fs/namei.c:4140
 __do_sys_unlink fs/namei.c:4217 [inline]
 __se_sys_unlink fs/namei.c:4215 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4215
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000ffffcf78 -> 0x00000000ffffce33

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 379 Comm: udevd Not tainted 5.15.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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