rxrpc: Be more selective about the types of received packets we accept

Currently, received RxRPC packets outside the range 1-13 are rejected.
There are, however, holes in the range that should also be rejected - plus
at least one type we don't yet support - so reject these also.

Signed-off-by: David Howells <dhowells@redhat.com>

2 files changed, 13 insertions, 1 deletions

diff --git a/include/rxrpc/packet.h b/include/rxrpc/packet.h
index de1e67988ada..9ebab3a8cf0a 100644
--- a/include/rxrpc/packet.h
+++ b/include/rxrpc/packet.h
@@ -70,6 +70,17 @@ struct rxrpc_wire_header {
 
 extern const char *rxrpc_pkts[];
 
+#define RXRPC_SUPPORTED_PACKET_TYPES (                  \
+                (1 << RXRPC_PACKET_TYPE_DATA) |         \
+                (1 << RXRPC_PACKET_TYPE_ACK) |          \
+                (1 << RXRPC_PACKET_TYPE_BUSY) |         \
+                (1 << RXRPC_PACKET_TYPE_ABORT) |        \
+                (1 << RXRPC_PACKET_TYPE_ACKALL) |       \
+                (1 << RXRPC_PACKET_TYPE_CHALLENGE) |    \
+                (1 << RXRPC_PACKET_TYPE_RESPONSE) |     \
+                /*(1 << RXRPC_PACKET_TYPE_DEBUG) | */   \
+                (1 << RXRPC_PACKET_TYPE_VERSION))
+
 /*****************************************************************************/
 /*
  * jumbo packet secondary header
diff --git a/net/rxrpc/ar-input.c b/net/rxrpc/ar-input.c
index e6396a8c969f..63ed75c40e29 100644
--- a/net/rxrpc/ar-input.c
+++ b/net/rxrpc/ar-input.c
@@ -728,7 +728,8 @@ void rxrpc_data_ready(struct sock *sk)
              sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
              sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber);
 
-        if (sp->hdr.type == 0 || sp->hdr.type >= RXRPC_N_PACKET_TYPES) {
+        if (sp->hdr.type >= RXRPC_N_PACKET_TYPES ||
+            !((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) {
                 _proto("Rx Bad Packet Type %u", sp->hdr.type);
                 goto bad_message;
         }