net/ulp: use consistent error code when blocking ULP

jira VULN-8789
cve-bf CVE-2023-0461
commit-author Paolo Abeni <pabeni@redhat.com>
commit 8ccc993

The referenced commit changed the error code returned by the kernel
when preventing a non-established socket from attaching the ktls
ULP. Before to such a commit, the user-space got ENOTCONN instead
of EINVAL.

The existing self-tests depend on such error code, and the change
caused a failure:

  RUN           global.non_established ...
 tls.c:1673:non_established:Expected errno (22) == ENOTCONN (107)
 non_established: Test failed at step #3
          FAIL  global.non_established

In the unlikely event existing applications do the same, address
the issue by restoring the prior error code in the above scenario.

Note that the only other ULP performing similar checks at init
time - smc_ulp_ops - also fails with ENOTCONN when trying to attach
the ULP to a non-established socket.

	Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Fixes: 2c02d41 ("net/ulp: prevent ULP without clone op from entering the LISTEN status")
	Signed-off-by: Paolo Abeni <pabeni@redhat.com>
	Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/7bb199e7a93317fb6f8bf8b9b2dc71c18f337cde.1674042685.git.pabeni@redhat.com
	Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit 8ccc993)
	Signed-off-by: Brett Mastbergen <bmastbergen@ciq.com>

# Conflicts:
#	net/ipv4/tcp_ulp.c

Author: bmastbergen

net/ipv4/tcp_ulp.c

@@ -131,7 +131,7 @@ static int __tcp_set_ulp(struct sock *sk, const struct tcp_ulp_ops *ulp_ops)
 	if (icsk->icsk_ulp_ops)
 		goto out_err;
 
-	err = -EINVAL;
+	err = -ENOTCONN;
 	if (!ulp_ops->clone && sk->sk_state == TCP_LISTEN)
 		goto out_err;