tls: rx: react to strparser initialization errors

Even though the normal strparser's init function has a return
value we got away with ignoring errors until now, as it only
validates the parameters and we were passing correct parameters.

tls_strp can fail to init on memory allocation errors, which
syzbot duly induced and reported.

Reported-by: syzbot+abd45eb849b05194b1b6@syzkaller.appspotmail.com
Fixes: 84c61fe1 ("tls: rx: do not use the standard strparser")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tls/tls_sw.c

@@ -2702,7 +2702,9 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 			crypto_info->version != TLS_1_3_VERSION &&
 			!!(tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC);
 
-		tls_strp_init(&sw_ctx_rx->strp, sk);
+		rc = tls_strp_init(&sw_ctx_rx->strp, sk);
+		if (rc)
+			goto free_aead;
 	}
 
 	goto out;