[moderation] [perf?] KCSAN: data-race in perf_event_set_state / perf_event_update_time (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 69b8923f5003 Merge tag 'for-linus-6.14-ofs4' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=110995f8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=723e332ac5000fb0
dashboard link: https://syzkaller.appspot.com/bug?extid=0dbb08866dfc54243101
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/b66d73c39df3/disk-69b8923f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ef1acf3bbc75/vmlinux-69b8923f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/debd69d37730/bzImage-69b8923f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0dbb08...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in perf_event_set_state / perf_event_update_time

write to 0xffff8881192f2380 of 8 bytes by task 4856 on cpu 0:
perf_event_update_time+0x14d/0x1b0 kernel/events/core.c:675
perf_mmap+0xac1/0xef0 kernel/events/core.c:6789
call_mmap include/linux/fs.h:2233 [inline]
mmap_file mm/internal.h:124 [inline]
__mmap_new_file_vma mm/vma.c:2292 [inline]
__mmap_new_vma mm/vma.c:2356 [inline]
__mmap_region mm/vma.c:2457 [inline]
mmap_region+0xc47/0x1620 mm/vma.c:2535
do_mmap+0x98a/0xc30 mm/mmap.c:561
vm_mmap_pgoff+0x16d/0x2d0 mm/util.c:575
ksys_mmap_pgoff+0x286/0x330 mm/mmap.c:607
x64_sys_call+0x1940/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:10
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 0xffff8881192f2380 of 8 bytes by task 4855 on cpu 1:
__perf_update_times kernel/events/core.c:662 [inline]
perf_event_update_time kernel/events/core.c:675 [inline]
perf_event_set_state+0x14b/0x3f0 kernel/events/core.c:694
event_sched_out+0x2c8/0x4a0 kernel/events/core.c:2335
group_sched_out kernel/events/core.c:2359 [inline]
__pmu_ctx_sched_out+0x22a/0x4e0 kernel/events/core.c:3332
ctx_sched_out+0x267/0x2c0 kernel/events/core.c:3420
task_ctx_sched_out kernel/events/core.c:2739 [inline]
perf_event_context_sched_out kernel/events/core.c:3664 [inline]
__perf_event_task_sched_out+0x438/0x1010 kernel/events/core.c:3763
perf_event_task_sched_out include/linux/perf_event.h:1561 [inline]
prepare_task_switch kernel/sched/core.c:5181 [inline]
context_switch kernel/sched/core.c:5324 [inline]
__schedule+0x957/0x990 kernel/sched/core.c:6764
__schedule_loop kernel/sched/core.c:6841 [inline]
schedule+0x55/0xc0 kernel/sched/core.c:6856
futex_wait_queue kernel/futex/waitwake.c:369 [inline]
__futex_wait+0x141/0x290 kernel/futex/waitwake.c:668
futex_wait+0x99/0x1c0 kernel/futex/waitwake.c:696
do_futex+0x276/0x370 kernel/futex/syscalls.c:102
__do_sys_futex kernel/futex/syscalls.c:179 [inline]
__se_sys_futex+0x25d/0x3a0 kernel/futex/syscalls.c:160
__x64_sys_futex+0x78/0x90 kernel/futex/syscalls.c:160
x64_sys_call+0x2d6a/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:203
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: 0x0000000000000000 -> 0x000000000005981e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4855 Comm: syz.0.512 Not tainted 6.13.0-syzkaller-09793-g69b8923f5003 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================


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[syzbot]

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