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, 11 insertions, 3 deletions

diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 44fa22b020ef..70e44abf106c 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -263,6 +263,8 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
 						    struct rxrpc_local *local,
 						    struct rxrpc_peer *peer,
 						    struct rxrpc_connection *conn,
+						    const struct rxrpc_security *sec,
+						    struct key *key,
 						    struct sk_buff *skb)
 {
 	struct rxrpc_backlog *b = rx->backlog;
@@ -310,7 +312,7 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
 		conn->params.local = rxrpc_get_local(local);
 		conn->params.peer = peer;
 		rxrpc_see_connection(conn);
-		rxrpc_new_incoming_connection(rx, conn, skb);
+		rxrpc_new_incoming_connection(rx, conn, sec, key, skb);
 	} else {
 		rxrpc_get_connection(conn);
 	}
@@ -349,9 +351,11 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
 					   struct sk_buff *skb)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	const struct rxrpc_security *sec = NULL;
 	struct rxrpc_connection *conn;
 	struct rxrpc_peer *peer = NULL;
-	struct rxrpc_call *call;
+	struct rxrpc_call *call = NULL;
+	struct key *key = NULL;
 
 	_enter("");
 
@@ -372,7 +376,11 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
 	 */
 	conn = rxrpc_find_connection_rcu(local, skb, &peer);
 
-	call = rxrpc_alloc_incoming_call(rx, local, peer, conn, skb);
+	if (!conn && !rxrpc_look_up_server_security(local, rx, &sec, &key, skb))
+		goto no_call;
+
+	call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, key, skb);
+	key_put(key);
 	if (!call) {
 		skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
 		goto no_call;