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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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