[moderation] [trace?] KCSAN: data-race in ring_buffer_poll_wait / ring_buffer_unlock_commit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: dac3e89a2c90 Merge tag 'drm-fixes-2026-08-15' of https://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=157f06c6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e71a508528491732
dashboard link: https://syzkaller.appspot.com/bug?extid=53ab168fdda7fba508ba
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [linux-...@vger.kernel.org linux-tra...@vger.kernel.org mathieu....@efficios.com mhir...@kernel.org ros...@goodmis.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e1e388931952/disk-dac3e89a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/81551c52c752/vmlinux-dac3e89a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7a78aff5261d/bzImage-dac3e89a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+53ab16...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in ring_buffer_poll_wait / ring_buffer_unlock_commit

write to 0xffff888100074cb4 of 1 bytes by task 9452 on cpu 1:
ring_buffer_poll_wait+0x14e/0x200 kernel/trace/ring_buffer.c:1079
trace_poll kernel/trace/trace.c:5323 [inline]
tracing_poll_pipe+0xf7/0x120 kernel/trace/trace.c:5332
vfs_poll include/linux/poll.h:82 [inline]
aio_poll_complete_work+0xd9/0x340 fs/aio.c:1786
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
worker_thread+0x569/0x750 kernel/workqueue.c:3486
kthread+0x221/0x270 kernel/kthread.c:436
ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888100074cb4 of 1 bytes by task 3299 on cpu 0:
rb_wakeups kernel/trace/ring_buffer.c:4297 [inline]
ring_buffer_unlock_commit+0x54/0x440 kernel/trace/ring_buffer.c:4498
__buffer_unlock_commit kernel/trace/trace.h:1697 [inline]
trace_buffer_unlock_commit_regs+0x43/0x310 kernel/trace/trace.c:2049
trace_event_buffer_commit+0x149/0x590 kernel/trace/trace.c:2024
do_trace_event_raw_event_kmalloc include/trace/events/kmem.h:57 [inline]
trace_event_raw_event_kmalloc+0xb6/0x110 include/trace/events/kmem.h:57
__do_trace_kmalloc include/trace/events/kmem.h:57 [inline]
trace_kmalloc include/trace/events/kmem.h:57 [inline]
__kmalloc_cache_noprof+0x30e/0x3d0 mm/slub.c:5487
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
netlbl_secattr_alloc_noprof include/net/netlabel.h:385 [inline]
selinux_netlbl_sock_genattr+0x88/0x260 security/selinux/netlabel.c:78
selinux_netlbl_socket_post_create+0x66/0x100 security/selinux/netlabel.c:404
selinux_socket_post_create+0x219/0x290 security/selinux/hooks.c:4981
security_socket_post_create+0x59/0xa0 security/security.c:4216
__sock_create+0x356/0x580 net/socket.c:1674
sock_create net/socket.c:1709 [inline]
__sys_socket_create net/socket.c:1746 [inline]
__sys_socket+0xaf/0x180 net/socket.c:1793
__do_sys_socket net/socket.c:1807 [inline]
__se_sys_socket net/socket.c:1805 [inline]
__x64_sys_socket+0x3f/0x50 net/socket.c:1805
x64_sys_call+0x11fc/0x3020 arch/x86/include/generated/asm/syscalls_64.h:42
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3299 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup