af_rxrpc: Fix XDR length check in rxrpc key demarshalling.

There may be padding on the ticket contained in the key payload, so just ensure
that the claimed token length is large enough, rather than exactly the right
size.

Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index 7633a752c65e99189c3e7603e2ebdd6e7438b356..0ad080790a32a341a1ddc57d632302563964a247 100644 (file)
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -99,7 +99,7 @@ static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
        _debug("tktlen: %x", tktlen);
        if (tktlen > AFSTOKEN_RK_TIX_MAX)
                return -EKEYREJECTED;
-       if (8 * 4 + tktlen != toklen)
+       if (toklen < 8 * 4 + tktlen)
                return -EKEYREJECTED;
 
        plen = sizeof(*token) + sizeof(*token->kad) + tktlen;