===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/monitor.c,v
retrieving revision 1.176
retrieving revision 1.177
diff -u -r1.176 -r1.177
--- src/usr.bin/ssh/monitor.c	2017/12/18 02:25:15	1.176
+++ src/usr.bin/ssh/monitor.c	2017/12/21 00:00:28	1.177
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.176 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: monitor.c,v 1.177 2017/12/21 00:00:28 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -1062,6 +1062,12 @@
 	  !monitor_allowed_key(blob, bloblen))
 		fatal("%s: bad key, not previously allowed", __func__);
 
+	/* Empty signature algorithm means NULL. */
+	if (*sigalg == '\0') {
+		free(sigalg);
+		sigalg = NULL;
+	}
+
 	/* XXX use sshkey_froms here; need to change key_blob, etc. */
 	if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
 		fatal("%s: bad public key blob: %s", __func__, ssh_err(r));
@@ -1092,6 +1098,7 @@
 	free(blob);
 	free(signature);
 	free(data);
+	free(sigalg);
 
 	monitor_reset_key_state();