rxrpc: Fix missing security check on incoming calls

Fix rxrpc_new_incoming_call() to check that we have a suitable service key
available for the combination of service ID and security class of a new
incoming call - and to reject calls for which we don't.

This causes an assertion like the following to appear:

	rxrpc: Assertion failed - 6(0x6) == 12(0xc) is false
	kernel BUG at net/rxrpc/call_object.c:456!

Where call->state is RXRPC_CALL_SERVER_SECURING (6) rather than
RXRPC_CALL_COMPLETE (12).

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 33 insertions, 37 deletions

diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
index a4c47d2b7054..9b1fb9ed0717 100644
--- a/net/rxrpc/security.c
+++ b/net/rxrpc/security.c
@@ -101,62 +101,58 @@ int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
 }
 
 /*
- * initialise the security on a server connection
+ * Find the security key for a server connection.
  */
-int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
+bool rxrpc_look_up_server_security(struct rxrpc_local *local, struct rxrpc_sock *rx,
+				   const struct rxrpc_security **_sec,
+				   struct key **_key,
+				   struct sk_buff *skb)
 {
 	const struct rxrpc_security *sec;
-	struct rxrpc_local *local = conn->params.local;
-	struct rxrpc_sock *rx;
-	struct key *key;
-	key_ref_t kref;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	key_ref_t kref = NULL;
 	char kdesc[5 + 1 + 3 + 1];
 
 	_enter("");
 
-	sprintf(kdesc, "%u:%u", conn->service_id, conn->security_ix);
+	sprintf(kdesc, "%u:%u", sp->hdr.serviceId, sp->hdr.securityIndex);
 
-	sec = rxrpc_security_lookup(conn->security_ix);
+	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
 	if (!sec) {
-		_leave(" = -ENOKEY [lookup]");
-		return -ENOKEY;
+		trace_rxrpc_abort(0, "SVS",
+				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+				  RX_INVALID_OPERATION, EKEYREJECTED);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = RX_INVALID_OPERATION;
+		return false;
 	}
 
-	/* find the service */
-	read_lock(&local->services_lock);
-	rx = rcu_dereference_protected(local->service,
-				       lockdep_is_held(&local->services_lock));
-	if (rx && (rx->srx.srx_service == conn->service_id ||
-		   rx->second_service == conn->service_id))
-		goto found_service;
+	if (sp->hdr.securityIndex == RXRPC_SECURITY_NONE)
+		goto out;
 
-	/* the service appears to have died */
-	read_unlock(&local->services_lock);
-	_leave(" = -ENOENT");
-	return -ENOENT;
-
-found_service:
 	if (!rx->securities) {
-		read_unlock(&local->services_lock);
-		_leave(" = -ENOKEY");
-		return -ENOKEY;
+		trace_rxrpc_abort(0, "SVR",
+				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+				  RX_INVALID_OPERATION, EKEYREJECTED);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = RX_INVALID_OPERATION;
+		return false;
 	}
 
 	/* look through the service's keyring */
 	kref = keyring_search(make_key_ref(rx->securities, 1UL),
 			      &key_type_rxrpc_s, kdesc, true);
 	if (IS_ERR(kref)) {
-		read_unlock(&local->services_lock);
-		_leave(" = %ld [search]", PTR_ERR(kref));
-		return PTR_ERR(kref);
+		trace_rxrpc_abort(0, "SVK",
+				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+				  sec->no_key_abort, EKEYREJECTED);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = sec->no_key_abort;
+		return false;
 	}
 
-	key = key_ref_to_ptr(kref);
-	read_unlock(&local->services_lock);
-
-	conn->server_key = key;
-	conn->security = sec;
-
-	_leave(" = 0");
-	return 0;
+out:
+	*_sec = sec;
+	*_key = key_ref_to_ptr(kref);
+	return true;
 }