* Fix segfault from receiving truncated DNS replies.

svn: 3791

doc/UPDATES

@@ -4,6 +4,7 @@
 * Fix leaf bots not updating behind other hubs (fixes #419)
 * Removed BDHASH as it wasn't even used.
 * SHELLHASH now supports SHA1 hashes.
+* Fix segfault from receiving truncated DNS replies.
 
 1.2.15 - http://wraith.botpack.net/milestone/1.2.15
 * Fix a possible segfault when binaries compiled wrong

src/adns.c

@@ -896,6 +896,11 @@ static int parse_reply(char *response, size_t nbytes)
 		}
 
 		ptr += reply.rdlength;
+                if ((size_t) (ptr - (unsigned char*) response) > nbytes) {
+                  sdprintf("MALFORMED/TRUNCATED DNS PACKET detected (need TCP).");
+                  q->remaining = 0;
+                  break;
+                }
 	}
 	/* Don't continue if we haven't gotten all expected replies. */
 	if (--q->remaining > 0) return 0;