[moderation] [kernel?] KCSAN: data-race in tick_nohz_handler / tick_nohz_idle_stop_tick

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 104db052b62d Merge tag 'spi-fix-v6.9-rc2' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=103f6fc5180000
kernel config: https://syzkaller.appspot.com/x/.config?x=d024e89f7bb376ce
dashboard link: https://syzkaller.appspot.com/bug?extid=0a160723683a406a5d65
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/99da4bc63d88/disk-104db052.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9075aca1010e/vmlinux-104db052.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3ec39fe6b51/bzImage-104db052.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0a1607...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in tick_nohz_handler / tick_nohz_idle_stop_tick

write to 0xffffffff8652ebb0 of 4 bytes by interrupt on cpu 0:
tick_sched_do_timer kernel/time/tick-sched.c:224 [inline]
tick_nohz_handler+0x2bc/0x2d0 kernel/time/tick-sched.c:287
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x214/0x5e0 kernel/time/hrtimer.c:1756
hrtimer_interrupt+0x210/0x7b0 kernel/time/hrtimer.c:1818
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
__sysvec_apic_timer_interrupt+0x5c/0x1a0 arch/x86/kernel/apic/apic.c:1049
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
__filemap_add_folio+0x4/0x700 mm/filemap.c:853
filemap_add_folio+0x70/0x160 mm/filemap.c:947
__filemap_get_folio+0x2f1/0x5b0 mm/filemap.c:1934
ext4_da_write_begin+0x2ef/0x550 fs/ext4/inode.c:2885
generic_perform_write+0x1d5/0x410 mm/filemap.c:3974
ext4_buffered_write_iter+0x1f6/0x380 fs/ext4/file.c:299
ext4_file_write_iter+0x29f/0xe30
__kernel_write_iter+0x265/0x490 fs/read_write.c:523
dump_emit_page fs/coredump.c:890 [inline]
dump_user_range+0x3a7/0x550 fs/coredump.c:951
elf_core_dump+0x1aa6/0x1bc0 fs/binfmt_elf.c:2077
do_coredump+0x1033/0x1890 fs/coredump.c:764
get_signal+0xdc1/0x1080 kernel/signal.c:2896
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
irqentry_exit_to_user_mode+0x94/0x130 kernel/entry/common.c:231
irqentry_exit+0x12/0x50 kernel/entry/common.c:334
exc_general_protection+0x33d/0x4d0 arch/x86/kernel/traps.c:644
asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617

read to 0xffffffff8652ebb0 of 4 bytes by task 0 on cpu 1:
tick_nohz_stop_tick kernel/time/tick-sched.c:1009 [inline]
tick_nohz_idle_stop_tick+0x19e/0x640 kernel/time/tick-sched.c:1217
cpuidle_idle_call kernel/sched/idle.c:232 [inline]
do_idle+0x178/0x230 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

value changed: 0xffffffff -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 6.9.0-rc2-syzkaller-00385-g104db052b62d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================


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