mptcp: fix security context on server socket

[ Upstream commit 0c14846 ]

Currently MPTCP is not propagating the security context
from the ingress request socket to newly created msk
at clone time.

Address the issue invoking the missing security helper.

Fixes: cf7da0d ("mptcp: Create SUBFLOW socket for incoming connections")
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Paolo Abeni

net/mptcp/protocol.c

@@ -2081,6 +2081,8 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
 	sock_reset_flag(nsk, SOCK_RCU_FREE);
 	/* will be fully established after successful MPC subflow creation */
 	inet_sk_state_store(nsk, TCP_SYN_RECV);
+
+	security_inet_csk_clone(nsk, req);
 	bh_unlock_sock(nsk);
 
 	/* keep a single reference */