[moderation] [kernel?] KCSAN: data-race in print_cpu / tick_nohz_stop_idle (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 977b1ef51866 Merge tag 'block-6.9-20240420' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=139ff520980000
kernel config: https://syzkaller.appspot.com/x/.config?x=eaea34ec4c9b6fb6
dashboard link: https://syzkaller.appspot.com/bug?extid=8f03f7153a596ac6fb8b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [anna-...@linutronix.de fred...@kernel.org linux-...@vger.kernel.org mi...@kernel.org tg...@linutronix.de]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/deeaf44a7761/disk-977b1ef5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/befb9e8ca501/vmlinux-977b1ef5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/558e81cc1437/bzImage-977b1ef5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8f03f7...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in print_cpu / tick_nohz_stop_idle

read-write to 0xffff888237d204b8 of 8 bytes by interrupt on cpu 1:
tick_sched_flag_clear kernel/time/tick-sched.c:201 [inline]
tick_nohz_stop_idle+0xd0/0x110 kernel/time/tick-sched.c:741
tick_nohz_irq_enter kernel/time/tick-sched.c:1541 [inline]
tick_irq_enter+0xa2/0x150 kernel/time/tick-sched.c:1567
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x66/0x80 arch/x86/kernel/apic/apic.c:1043
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]
arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112
acpi_idle_do_entry+0x1d/0x30 drivers/acpi/processor_idle.c:573
acpi_idle_enter+0x96/0xb0 drivers/acpi/processor_idle.c:707
cpuidle_enter_state+0xcf/0x270 drivers/cpuidle/cpuidle.c:267
cpuidle_enter+0x40/0x70 drivers/cpuidle/cpuidle.c:388
call_cpuidle kernel/sched/idle.c:155 [inline]
cpuidle_idle_call kernel/sched/idle.c:236 [inline]
do_idle+0x195/0x230 kernel/sched/idle.c:332
cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:430
start_secondary+0x94/0xa0 arch/x86/kernel/smpboot.c:313
common_startup_64+0x12c/0x137

read to 0xffff888237d204b8 of 8 bytes by task 19797 on cpu 0:
print_cpu+0x3dd/0x670 kernel/time/timer_list.c:155
timer_list_show+0x115/0x180 kernel/time/timer_list.c:295
seq_read_iter+0x65b/0x940 fs/seq_file.c:272
proc_reg_read_iter+0x11e/0x190 fs/proc/inode.c:299
call_read_iter include/linux/fs.h:2104 [inline]
copy_splice_read+0x3a4/0x5d0 fs/splice.c:365
do_splice_read fs/splice.c:985 [inline]
splice_direct_to_actor+0x26c/0x670 fs/splice.c:1089
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x3b9/0x970 fs/read_write.c:1295
__do_sys_sendfile64 fs/read_write.c:1362 [inline]
__se_sys_sendfile64 fs/read_write.c:1348 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
x64_sys_call+0x2c67/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:41
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000035 -> 0x0000000000000030

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19797 Comm: syz-executor.0 Not tainted 6.9.0-rc4-syzkaller-00266-g977b1ef51866 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================


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