===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh-ed25519.c,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -r1.6 -r1.7
--- src/usr.bin/ssh/ssh-ed25519.c	2015/01/15 21:38:50	1.6
+++ src/usr.bin/ssh/ssh-ed25519.c	2016/04/21 06:08:02	1.7
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-ed25519.c,v 1.6 2015/01/15 21:38:50 markus Exp $ */
+/* $OpenBSD: ssh-ed25519.c,v 1.7 2016/04/21 06:08:02 djm Exp $ */
 /*
  * Copyright (c) 2013 Markus Friedl <markus@openbsd.org>
  *
@@ -104,7 +104,8 @@
 	if (key == NULL ||
 	    sshkey_type_plain(key->type) != KEY_ED25519 ||
 	    key->ed25519_pk == NULL ||
-	    datalen >= INT_MAX - crypto_sign_ed25519_BYTES)
+	    datalen >= INT_MAX - crypto_sign_ed25519_BYTES ||
+	    signature == NULL || signaturelen == 0)
 		return SSH_ERR_INVALID_ARGUMENT;
 
 	if ((b = sshbuf_from(signature, signaturelen)) == NULL)