Commit 12083d72 authored by Dmitry Safonov's avatar Dmitry Safonov Committed by Paolo Abeni
Browse files

net/tcp: Don't add key with non-matching VRF on connected sockets 



If the connection was established, don't allow adding TCP-AO keys that
don't match the peer. Currently, there are checks for ip-address
matching, but L3 index check is missing. Add it to restrict userspace
shooting itself somewhere.

Yet, nothing restricts the CAP_NET_RAW user from trying to shoot
themselves by performing setsockopt(SO_BINDTODEVICE) or
setsockopt(SO_BINDTOIFINDEX) over an established TCP-AO connection.
So, this is just "minimum effort" to potentially save someone's
debugging time, rather than a full restriction on doing weird things.

Fixes: 248411b8 ("net/tcp: Wire up l3index to TCP-AO")
Signed-off-by: default avatarDmitry Safonov <dima@arista.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 965c00e4

net/ipv4/tcp_ao.c

+9 −0
Original line number Diff line number Diff line
@@ -1608,6 +1608,15 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family, 
		if (!dev || !l3index)

			return -EINVAL;



		if (!bound_dev_if || bound_dev_if != cmd.ifindex) {

			/* tcp_ao_established_key() doesn't expect having

			 * non peer-matching key on an established TCP-AO

			 * connection.

			 */

			if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))

				return -EINVAL;

		}



		/* It's still possible to bind after adding keys or even

		 * re-bind to a different dev (with CAP_NET_RAW).

		 * So, no reason to return error here, rather try to be