Currently subflow_finish_connect() changes unconditionally
any msk socket status other than TCP_ESTABLISHED.
If an unblocking connect() races with close(), we can end-up
triggering:
IPv4: Attempt to release TCP socket in state 1 00000000e32b8b7e
when the msk socket is disposed.
Be sure to enter the established status only from SYN_SENT.
Fixes: c3c123d16c ("net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1200832c6e