syzbot

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BUG: KCSAN: data-race in tipc_poll / tipc_sk_conn_proto_rcv

write to 0xffff88812d8a4b7e of 2 bytes by task 44 on cpu 1:
 tipc_sk_conn_proto_rcv+0x392/0x720 net/tipc/socket.c:1370
 tipc_sk_proto_rcv net/tipc/socket.c:2157 [inline]
 tipc_sk_filter_rcv+0x1b19/0x1f50 net/tipc/socket.c:2351
 tipc_sk_enqueue+0x2b9/0xa00 net/tipc/socket.c:2444
 tipc_sk_rcv+0x23c/0x5e0 net/tipc/socket.c:2496
 tipc_node_xmit+0x1f6/0xb00 net/tipc/node.c:1695
 tipc_node_xmit_skb+0xb2/0xe0 net/tipc/node.c:1755
 tipc_sk_send_ack+0x251/0x260 net/tipc/socket.c:1827
 tipc_recvmsg+0x7cf/0x9b0 net/tipc/socket.c:1995
 sock_recvmsg_nosec net/socket.c:948 [inline]
 sock_recvmsg+0x87/0xa0 net/socket.c:966
 tipc_conn_rcv_from_sock net/tipc/topsrv.c:398 [inline]
 tipc_conn_recv_work+0x130/0x2a0 net/tipc/topsrv.c:421
 process_one_work+0x3e3/0x970 kernel/workqueue.c:2289
 worker_thread+0x638/0xaa0 kernel/workqueue.c:2436
 kthread+0x1bf/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffff88812d8a4b7e of 2 bytes by task 14856 on cpu 0:
 tsk_conn_cong net/tipc/socket.c:224 [inline]
 tipc_poll+0x1d9/0x340 net/tipc/socket.c:807
 sock_poll+0x23e/0x260 net/socket.c:1306
 vfs_poll include/linux/poll.h:88 [inline]
 p9_fd_poll net/9p/trans_fd.c:233 [inline]
 p9_conn_create+0x218/0x300 net/9p/trans_fd.c:597
 p9_fd_create+0x1e3/0x1f0 net/9p/trans_fd.c:1076
 p9_client_create+0x59a/0x750 net/9p/client.c:1037
 v9fs_session_init+0x100/0xcf0 fs/9p/v9fs.c:408
 v9fs_mount+0x57/0x520 fs/9p/vfs_super.c:126
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1497
 do_new_mount fs/namespace.c:3039 [inline]
 path_mount+0x11cf/0x1c40 fs/namespace.c:3369
 do_mount fs/namespace.c:3382 [inline]
 __do_sys_mount fs/namespace.c:3590 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3567
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3567
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0208 -> 0x0104

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14856 Comm: syz-executor.4 Not tainted 5.17.0-syzkaller-13673-ge8b767f5e040-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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