gpg: Fix memory leak in the error case of signature creation.

* g10/sign.c (write_signature_packets): Free SIG.  Also replace
xcalloc by xtrycalloc.
--

If do_sign fails SIG was not released.  Note that in the good case SIG
is transferred to PKT and freed by free_packet.

Reported-by: Stephan Müller
Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit 5996c7bf99f3a681393fd9589276399ebc956cff)

Gbp-Pq: Name 0034-gpg-Fix-memory-leak-in-the-error-case-of-signature-c.patch

diff --git a/g10/sign.c b/g10/sign.c
index acc894c498dc0b27b910f0223f477fb2603ed92e..ff099b31c06a58fbc517231e19012918b35db3c5 100644 (file)
--- a/g10/sign.c
+++ b/g10/sign.c
@@ -686,7 +686,10 @@ write_signature_packets (SK_LIST sk_list, IOBUF out, gcry_md_hd_t hash,
       pk = sk_rover->pk;
 
       /* Build the signature packet.  */
-      sig = xmalloc_clear (sizeof *sig);
+      sig = xtrycalloc (1, sizeof *sig);
+      if (!sig)
+        return gpg_error_from_syserror ();
+
       if (duration || opt.sig_policy_url
           || opt.sig_notations || opt.sig_keyserver_url)
         sig->version = 4;
@@ -731,8 +734,12 @@ write_signature_packets (SK_LIST sk_list, IOBUF out, gcry_md_hd_t hash,
             print_status_sig_created (pk, sig, status_letter);
           free_packet (&pkt);
           if (rc)
-            log_error ("build signature packet failed: %s\n", gpg_strerror (rc));
+            log_error ("build signature packet failed: %s\n",
+                       gpg_strerror (rc));
        }
+      else
+        xfree (sig);
+
       if (rc)
         return rc;
     }