X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/941d39e21d83e4db76f354e6782e24b216027965..717dc4839a39d4235793d152f39fd24e9be9d12b:/ssh.c

diff --git a/ssh.c b/ssh.c
index 0edaf932..acc4598b 100644
--- a/ssh.c
+++ b/ssh.c
@@ -885,6 +885,15 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen)
     st->pad = pktin.data[4];
 
     /*
+     * _Completely_ silly lengths should be stomped on before they
+     * do us any more damage.
+     */
+    if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
+	bombout(("Incoming packet was garbled on decryption"));
+	crReturn(0);
+    }
+
+    /*
      * This enables us to deduce the payload length.
      */
     st->payload = st->len - st->pad - 1;