[moderation] [perf?] KCSAN: data-race in perf_event_update_userpage / perf_event_update_userpage (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2c22dc1ee3a1 Merge tag 'mailbox-v6.13' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=146c1530580000
kernel config: https://syzkaller.appspot.com/x/.config?x=db310a9aeec0c8cb
dashboard link: https://syzkaller.appspot.com/bug?extid=41e004d051e6772142c9
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ac...@kernel.org adrian...@intel.com alexander...@linux.intel.com iro...@google.com jo...@kernel.org kan....@linux.intel.com linux-...@vger.kernel.org linux-pe...@vger.kernel.org mark.r...@arm.com mi...@redhat.com namh...@kernel.org pet...@infradead.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0cb07ee98241/disk-2c22dc1e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ba989cf0a9bd/vmlinux-2c22dc1e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b7e2933ec9ca/bzImage-2c22dc1e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+41e004...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in perf_event_update_userpage / perf_event_update_userpage

write to 0xffff8881346ef010 of 8 bytes by task 32165 on cpu 0:
perf_event_update_userpage+0x2fa/0x460 kernel/events/core.c:6260
cpu_clock_event_add+0x116/0x130 kernel/events/core.c:11374
event_sched_in+0x47c/0x6d0 kernel/events/core.c:2620
group_sched_in kernel/events/core.c:2653 [inline]
merge_sched_in kernel/events/core.c:3924 [inline]
visit_groups_merge+0xc26/0x1c00 kernel/events/core.c:3869
pmu_groups_sched_in kernel/events/core.c:3951 [inline]
__pmu_ctx_sched_in+0xc8/0xf0 kernel/events/core.c:3963
ctx_sched_in+0x361/0x3b0 kernel/events/core.c:4014
perf_event_sched_in kernel/events/core.c:2751 [inline]
perf_event_context_sched_in kernel/events/core.c:4061 [inline]
__perf_event_task_sched_in+0x56a/0xa10 kernel/events/core.c:4090
perf_event_task_sched_in include/linux/perf_event.h:1517 [inline]
finish_task_switch+0x218/0x2b0 kernel/sched/core.c:5238
context_switch kernel/sched/core.c:5372 [inline]
__schedule+0x6fa/0x930 kernel/sched/core.c:6756
__schedule_loop kernel/sched/core.c:6833 [inline]
schedule+0x55/0xc0 kernel/sched/core.c:6848
exit_to_user_mode_loop kernel/entry/common.c:102 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x42/0x120 kernel/entry/common.c:218
do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff8881346ef010 of 8 bytes by task 32163 on cpu 1:
perf_event_update_userpage+0x382/0x460 kernel/events/core.c:6260
_perf_event_reset+0x36/0x40 kernel/events/core.c:5859
perf_event_for_each_child kernel/events/core.c:5894 [inline]
perf_event_for_each kernel/events/core.c:5910 [inline]
_perf_ioctl kernel/events/core.c:6107 [inline]
perf_ioctl+0x41a/0x1550 kernel/events/core.c:6126
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xc9/0x140 fs/ioctl.c:892
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:892
x64_sys_call+0x1690/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:17
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: 0x0000000000017c5b -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 32163 Comm: syz.4.8880 Not tainted 6.12.0-syzkaller-09435-g2c22dc1ee3a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.