[moderation] [kernel?] KCSAN: data-race in hrtimer_reprogram / print_cpu (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 83a7eefedc9b Linux 6.10-rc3
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1065bbce980000
kernel config: https://syzkaller.appspot.com/x/.config?x=68336ea4b6f4fc09
dashboard link: https://syzkaller.appspot.com/bug?extid=15ce54add047ef6c0921
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 tg...@linutronix.de]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dc4448d7f810/disk-83a7eefe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d1b7e727f29b/vmlinux-83a7eefe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/470dd9374113/bzImage-83a7eefe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+15ce54...@syzkaller.appspotmail.com

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

write to 0xffff888237d1ffa0 of 8 bytes by task 15484 on cpu 1:
__hrtimer_reprogram kernel/time/hrtimer.c:657 [inline]
hrtimer_reprogram+0x1a2/0x220 kernel/time/hrtimer.c:864
hrtimer_start_range_ns+0x4ee/0x560 kernel/time/hrtimer.c:1301
hrtimer_start_expires include/linux/hrtimer.h:289 [inline]
hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1949 [inline]
do_nanosleep+0x86/0x300 kernel/time/hrtimer.c:2025
hrtimer_nanosleep+0xe8/0x1e0 kernel/time/hrtimer.c:2081
common_nsleep+0x68/0x90 kernel/time/posix-timers.c:1350
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline]
__se_sys_clock_nanosleep+0x20a/0x240 kernel/time/posix-timers.c:1373
__x64_sys_clock_nanosleep+0x55/0x70 kernel/time/posix-timers.c:1373
x64_sys_call+0x24ad/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:231
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d1ffa0 of 8 bytes by task 15485 on cpu 0:
print_cpu+0x2fb/0x670 kernel/time/timer_list.c:133
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
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+0x3ab/0x960 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+0x2c9f/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:41
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000453875fd00 -> 0x000000453871d96a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15485 Comm: syz-executor.4 Tainted: G W 6.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================


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