mainline inclusion
from mainline-5.10.62
commit 0a178a01516158caeb3aa26c1b54d50ad12333f6
bugzilla: 182217 https://gitee.com/openeuler/kernel/issues/I4EFOS

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0a178a01516158caeb3aa26c1b54d50ad12333f6

--------------------------------

commit 7387a72c upstream.

__tipc_sendmsg() is called to send SYN packet by either tipc_sendmsg()
or tipc_connect(). The difference is in tipc_connect(), it will call
tipc_wait_for_connect() after __tipc_sendmsg() to wait until connecting
is done. So there's no need to wait in __tipc_sendmsg() for this case.

This patch is to fix it by calling tipc_wait_for_connect() only when dlen
is not 0 in __tipc_sendmsg(), which means it's called by tipc_connect().

Note this also fixes the failure in tipcutils/test/ptts/:

  # ./tipcTS &
  # ./tipcTC 9
  (hang)

Fixes: 36239dab6da7 ("tipc: fix implicit-connect for SYN+")
Reported-by: NShuang Li <shuali@redhat.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>