syzbot

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BUG: KCSAN: data-race in hrtimer_reprogram / print_cpu

write to 0xffff888237d1b8a0 of 8 bytes by task 11557 on cpu 1:
 __hrtimer_reprogram kernel/time/hrtimer.c:664 [inline]
 hrtimer_reprogram+0x1a5/0x220 kernel/time/hrtimer.c:869
 hrtimer_start_range_ns+0xd0f/0x10f0 kernel/time/hrtimer.c:1331
 hrtimer_start_expires include/linux/hrtimer.h:258 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2047 [inline]
 do_nanosleep+0x78/0x330 kernel/time/hrtimer.c:2121
 hrtimer_nanosleep+0x207/0x3e0 kernel/time/hrtimer.c:2171
 common_nsleep+0x62/0x80 kernel/time/posix-timers.c:1345
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline]
 __se_sys_clock_nanosleep+0x223/0x260 kernel/time/posix-timers.c:1368
 __x64_sys_clock_nanosleep+0x55/0x70 kernel/time/posix-timers.c:1368
 x64_sys_call+0x146e/0x3020 arch/x86/include/generated/asm/syscalls_64.h:231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d1b8a0 of 8 bytes by task 11603 on cpu 0:
 print_cpu+0x2ea/0x660 kernel/time/timer_list.c:131
 timer_list_show+0x107/0x170 kernel/time/timer_list.c:293
 seq_read_iter+0x31e/0x940 fs/seq_file.c:231
 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/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000003c55f29900 -> 0x0000003c55e5de1b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 11603 Comm: syz.1.1902 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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