syzbot

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BUG: KCSAN: data-race in hrtimer_reprogram / print_cpu

write to 0xffff888237c1b260 of 8 bytes by task 21809 on cpu 0:
 __hrtimer_reprogram kernel/time/hrtimer.c:663 [inline]
 hrtimer_reprogram+0x1a5/0x220 kernel/time/hrtimer.c:868
 hrtimer_start_range_ns+0x6b2/0x740 kernel/time/hrtimer.c:1330
 hrtimer_start_expires include/linux/hrtimer.h:277 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2023 [inline]
 do_nanosleep+0x79/0x330 kernel/time/hrtimer.c:2097
 hrtimer_nanosleep+0xdd/0x280 kernel/time/hrtimer.c:2147
 common_nsleep+0x62/0x80 kernel/time/posix-timers.c:1353
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline]
 __se_sys_clock_nanosleep+0x21a/0x250 kernel/time/posix-timers.c:1376
 __x64_sys_clock_nanosleep+0x55/0x70 kernel/time/posix-timers.c:1376
 x64_sys_call+0x272d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:231
 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 0xffff888237c1b260 of 8 bytes by task 21830 on cpu 1:
 print_cpu+0x30b/0x680 kernel/time/timer_list.c:133
 timer_list_show+0x107/0x170 kernel/time/timer_list.c:295
 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: 0x0000003ef421889f -> 0x0000003ef4214b44

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 21830 Comm: syz.6.3611 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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