syzbot

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BUG: KCSAN: data-race in print_cpu / tick_nohz_stop_idle

write to 0xffff888237d1b838 of 8 bytes by interrupt on cpu 1:
 tick_nohz_stop_idle+0xbf/0x120 kernel/time/tick-sched.c:738
 tick_nohz_irq_enter kernel/time/tick-sched.c:1528 [inline]
 tick_irq_enter+0xa1/0x150 kernel/time/tick-sched.c:1554
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x67/0x80 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
 pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x3d/0x70 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0xcb/0x240 kernel/sched/idle.c:330
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:428
 start_secondary+0x95/0xa0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147

read to 0xffff888237d1b838 of 8 bytes by task 6552 on cpu 0:
 print_cpu+0x502/0x680 kernel/time/timer_list.c:162
 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+0x3c4/0x5f0 fs/splice.c:363
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 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: 0x000000188cb583c9 -> 0x000000188cb6ebae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6552 Comm: syz.4.949 Not tainted 6.16.0-syzkaller-10355-gf2d282e1dfb3 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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