syzbot

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BUG: KCSAN: data-race in clockevents_program_event / print_tickdevice

write to 0xffff888237d17ba0 of 8 bytes by task 13959 on cpu 1:
 clockevents_program_event+0x46/0x340 kernel/time/clockevents.c:347
 tick_program_event+0x79/0xc0 kernel/time/tick-oneshot.c:48
 hrtimer_rearm_event kernel/time/hrtimer.c:707 [inline]
 hrtimer_rearm kernel/time/hrtimer.c:2039 [inline]
 __hrtimer_rearm_deferred+0x571/0x670 kernel/time/hrtimer.c:2059
 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline]
 hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline]
 irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
 irqentry_exit+0x55c/0x5d0 kernel/entry/common.c:164
 sysvec_apic_timer_interrupt+0x44/0x80 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:198
 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
 unlock_task_sighand include/linux/sched/signal.h:749 [inline]
 do_send_sig_info+0xb8/0xf0 kernel/signal.c:1268
 send_sig_info kernel/signal.c:1619 [inline]
 send_sig_perf+0xdf/0x110 kernel/signal.c:1798
 perf_sigtrap kernel/events/core.c:7593 [inline]
 perf_pending_task+0x17c/0x210 kernel/events/core.c:7697
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 resume_user_mode_work+0x73/0x90 include/linux/resume_user_mode.h:50
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
 irqentry_exit+0x156/0x5d0 kernel/entry/common.c:162
 sysvec_apic_timer_interrupt+0x44/0x80 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

read to 0xffff888237d17ba0 of 8 bytes by task 13960 on cpu 0:
 print_tickdevice+0x142/0x340 kernel/time/timer_list.c:204
 timer_list_show+0x6c/0x170 kernel/time/timer_list.c:296
 seq_read_iter+0x636/0x940 fs/seq_file.c:273
 proc_reg_read_iter+0x110/0x180 fs/proc/inode.c:299
 copy_splice_read+0x471/0x6c0 fs/splice.c:362
 do_splice_read fs/splice.c:980 [inline]
 splice_direct_to_actor+0x26e/0x670 fs/splice.c:1084
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1228
 do_sendfile+0x382/0x650 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419
 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x7fffffffffffffff -> 0x000000470cbc4512

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 13960 Comm: syz.5.1539 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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