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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13731649580000
kernel config: https://syzkaller.appspot.com/x/.config?x=84b3039e8461eef5
dashboard link: https://syzkaller.appspot.com/bug?extid=0168fe25f9e5d46bd5fe
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d1a0ae21bd78/disk-848acc8f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9be505d18eb6/vmlinux-848acc8f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8ab6a3838bc0/bzImage-848acc8f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0168fe...@syzkaller.appspotmail.com

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

write to 0xffff888100074cb4 of 1 bytes by task 8271 on cpu 1:
rb_wakeups kernel/trace/ring_buffer.c:4295 [inline]
ring_buffer_unlock_commit+0x6a/0x440 kernel/trace/ring_buffer.c:4495
__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_hrtimer_setup include/trace/events/timer.h:193 [inline]
trace_event_raw_event_hrtimer_setup+0xc9/0x170 include/trace/events/timer.h:193
__do_trace_hrtimer_setup include/trace/events/timer.h:193 [inline]
trace_hrtimer_setup include/trace/events/timer.h:193 [inline]
debug_setup_on_stack kernel/time/hrtimer.c:523 [inline]
hrtimer_setup_sleeper_on_stack+0xd1/0xf0 kernel/time/hrtimer.c:2366
schedule_hrtimeout_range_clock+0x71/0x1a0 kernel/time/sleep_timeout.c:211
schedule_hrtimeout_range+0x28/0x40 kernel/time/sleep_timeout.c:263
poll_schedule_timeout fs/select.c:241 [inline]
do_select+0xed3/0xfa0 fs/select.c:603
core_sys_select+0x453/0x730 fs/select.c:677
do_pselect fs/select.c:770 [inline]
__do_sys_pselect6 fs/select.c:809 [inline]
__se_sys_pselect6+0x23f/0x2a0 fs/select.c:800
__x64_sys_pselect6+0x78/0x90 fs/select.c:800
x64_sys_call+0x8d5/0x3020 arch/x86/include/generated/asm/syscalls_64.h:271
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

read to 0xffff888100074cb4 of 1 bytes by task 8264 on cpu 0:
rb_wakeups kernel/trace/ring_buffer.c:4294 [inline]
ring_buffer_unlock_commit+0x54/0x440 kernel/trace/ring_buffer.c:4495
__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_sock_msg_length include/trace/events/sock.h:267 [inline]
trace_event_raw_event_sock_msg_length+0x10f/0x1c0 include/trace/events/sock.h:267
__do_trace_sock_recv_length include/trace/events/sock.h:304 [inline]
trace_sock_recv_length include/trace/events/sock.h:304 [inline]
call_trace_sock_recv_length+0xa2/0xc0 net/socket.c:1120
sock_recvmsg_nosec+0xdf/0xf0 net/socket.c:1131
____sys_recvmsg+0x26f/0x280 net/socket.c:2902
___sys_recvmsg+0x11f/0x3a0 net/socket.c:2946
do_recvmmsg+0x1e5/0x560 net/socket.c:3041
__sys_recvmmsg net/socket.c:3115 [inline]
__do_sys_recvmmsg net/socket.c:3138 [inline]
__se_sys_recvmmsg net/socket.c:3131 [inline]
__x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3131
x64_sys_call+0x80f/0x3020 arch/x86/include/generated/asm/syscalls_64.h:300
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: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8264 Comm: syz.5.1654 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================


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