[moderation] [audit?] KCSAN: data-race in audit_log_start / audit_receive (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d58772d8520c Merge tag 'regmap-fix-v7.2-rc7' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11afe079580000
kernel config: https://syzkaller.appspot.com/x/.config?x=33c5ac947f6be69e
dashboard link: https://syzkaller.appspot.com/bug?extid=39b8fea0641107a1ccee
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [au...@vger.kernel.org epa...@redhat.com linux-...@vger.kernel.org pa...@paul-moore.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f07cf409b24b/disk-d58772d8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cc40e664d80c/vmlinux-d58772d8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/677c7e08cc04/bzImage-d58772d8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+39b8fe...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in audit_log_start / audit_receive

write to 0xffffffff893dbb98 of 8 bytes by task 18825 on cpu 1:
audit_ctl_unlock kernel/audit.c:258 [inline]
audit_receive+0x1d2a/0x1ea0 kernel/audit.c:1627
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x5a7/0x680 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x5be/0x6f0 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x532/0x580 net/socket.c:2684
___sys_sendmsg+0x195/0x1e0 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0xd4/0x160 net/socket.c:2773
x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
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 0xffffffff893dbb98 of 8 bytes by task 18823 on cpu 0:
audit_ctl_owner_current kernel/audit.c:271 [inline]
audit_log_start+0x103/0x730 kernel/audit.c:1933
audit_seccomp+0x49/0x110 kernel/auditsc.c:2948
seccomp_log kernel/seccomp.c:1048 [inline]
__seccomp_filter+0x121a/0x1370 kernel/seccomp.c:1376
__secure_computing+0x7d/0x150 kernel/seccomp.c:1404
syscall_trace_enter include/linux/entry-common.h:103 [inline]
syscall_enter_from_user_mode_work include/linux/entry-common.h:147 [inline]
syscall_enter_from_user_mode include/linux/entry-common.h:178 [inline]
do_syscall_64+0xd4/0x3c0 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88810210e780 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 18823 Comm: syz.3.3476 Tainted: G W syzkaller #0 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================


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