--- pk-libgcrypt.c-	2009-04-23 10:59:06.000000000 +0200
+++ pk-libgcrypt.c	2009-04-23 18:32:17.000000000 +0200
@@ -418,7 +418,7 @@
 		      const gnutls_datum_t * signature,
 		      const gnutls_pk_params_st * pk_params)
 {
-  gcry_sexp_t s_sig, s_hash, s_pkey;
+  gcry_sexp_t s_sig = NULL, s_hash = NULL, s_pkey = NULL;
   int rc = -1, ret;
   bigint_t hash;
   bigint_t tmp[2] = { NULL, NULL };
@@ -511,6 +511,7 @@
   gcry_sexp_release (s_sig);
   gcry_sexp_release (s_hash);
   gcry_sexp_release (s_pkey);
+  s_hash = s_pkey = s_sig = NULL;
 
   if (rc != 0)
     {