syzbot

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BUG: KCSAN: data-race in clockevents_program_event / print_tickdevice

write to 0xffff888237d17758 of 8 bytes by interrupt on cpu 1:
 clockevents_program_event+0x3f/0x4e0 kernel/time/clockevents.c:313
 tick_program_event+0x79/0xc0 kernel/time/tick-oneshot.c:44
 hrtimer_interrupt+0x25e/0x460 kernel/time/hrtimer.c:1900
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 __tsan_read8+0x12/0x190 kernel/kcsan/core.c:1025
 tty_driver_lookup_tty drivers/tty/tty_io.c:1219 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:2045 [inline]
 tty_open+0x225/0xaf0 drivers/tty/tty_io.c:2120
 chrdev_open+0x2eb/0x3a0 fs/char_dev.c:414
 do_dentry_open+0x646/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4046
 do_filp_open+0x109/0x230 fs/namei.c:4073
 do_sys_openat2+0xa6/0x110 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1461
 x64_sys_call+0x2e9c/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d17758 of 8 bytes by task 5977 on cpu 0:
 print_tickdevice+0x142/0x340 kernel/time/timer_list.c:208
 timer_list_show+0x6c/0x170 kernel/time/timer_list.c:300
 seq_read_iter+0x627/0x940 fs/seq_file.c:272
 proc_reg_read_iter+0x10d/0x180 fs/proc/inode.c:299
 copy_splice_read+0x442/0x660 fs/splice.c:363
 do_splice_read fs/splice.c:982 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1086
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2bb0/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x7fffffffffffffff -> 0x0000001290da6bbb

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 5977 Comm: syz.1.995 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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