[moderation] [tipc?] KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv (7)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c8ebd433459b Merge tag 'nfsd-6.19-2' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=161a5792580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b319ff1b6a2797ca
dashboard link: https://syzkaller.appspot.com/bug?extid=c2554c7622dd36deb461
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [da...@davemloft.net edum...@google.com ho...@kernel.org jma...@redhat.com ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com tipc-di...@lists.sourceforge.net]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d4c0e188b92f/disk-c8ebd433.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/25522cdc5fa6/vmlinux-c8ebd433.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a1499d747012/bzImage-c8ebd433.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c2554c...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in tipc_poll / tipc_sk_proto_rcv

read-write to 0xffff888103c5a166 of 2 bytes by task 23759 on cpu 1:
tipc_sk_conn_proto_rcv net/tipc/socket.c:1367 [inline]
tipc_sk_proto_rcv+0x66e/0xb00 net/tipc/socket.c:2156
tipc_sk_filter_rcv+0x18ea/0x1a00 net/tipc/socket.c:2350
tipc_sk_enqueue net/tipc/socket.c:2443 [inline]
tipc_sk_rcv+0x4dc/0x18b0 net/tipc/socket.c:2495
tipc_node_xmit+0x18b/0x890 net/tipc/node.c:1701
tipc_node_xmit_skb+0x91/0xc0 net/tipc/node.c:1766
tipc_sk_send_ack+0x25c/0x270 net/tipc/socket.c:1824
tipc_recvmsg+0x809/0x9d0 net/tipc/socket.c:1992
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x139/0x170 net/socket.c:1100
tipc_conn_rcv_from_sock net/tipc/topsrv.c:401 [inline]
tipc_conn_recv_work+0x13d/0x280 net/tipc/topsrv.c:424
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
worker_thread+0x582/0x770 kernel/workqueue.c:3421
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffff888103c5a166 of 2 bytes by task 10968 on cpu 0:
tsk_conn_cong net/tipc/socket.c:222 [inline]
tipc_poll+0x1f9/0x350 net/tipc/socket.c:806
sock_poll+0x20d/0x230 net/socket.c:1443
vfs_poll include/linux/poll.h:82 [inline]
__io_arm_poll_handler+0x1ee/0xb70 io_uring/poll.c:581
io_poll_add+0x69/0xe0 io_uring/poll.c:899
__io_issue_sqe+0xfe/0x2e0 io_uring/io_uring.c:1792
io_issue_sqe+0x56/0xa80 io_uring/io_uring.c:1815
io_queue_sqe io_uring/io_uring.c:2042 [inline]
io_submit_sqe io_uring/io_uring.c:2320 [inline]
io_submit_sqes+0x78b/0x11b0 io_uring/io_uring.c:2434
__do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
__se_sys_io_uring_enter+0x1bd/0x1a30 io_uring/io_uring.c:3219
__x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3219
x64_sys_call+0x27e4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:427
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0208 -> 0x0104

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10968 Comm: syz.4.13458 Tainted: G W syzkaller #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================


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