auth: Fix memory leak in ssh_userauth_publickey_auto()

When a key is rejected, free the allocated memory before returning.

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/auth.c

@@ -1132,7 +1132,9 @@ int ssh_userauth_publickey_auto(ssh_session session,
                         "Public key authentication error for %s",
                         privkey_file);
                 ssh_key_free(state->privkey);
+                state->privkey = NULL;
                 ssh_key_free(state->pubkey);
+                state->pubkey = NULL;
                 SAFE_FREE(session->auth.auto_state);
                 return rc;
             } else if (rc == SSH_AUTH_AGAIN) {
@@ -1198,6 +1200,9 @@ int ssh_userauth_publickey_auto(ssh_session session,
                 return rc;
             }
 
+            ssh_key_free(state->privkey);
+            ssh_key_free(state->pubkey);
+
             SSH_LOG(SSH_LOG_WARN,
                     "The server accepted the public key but refused the signature");
             state->it = state->it->next;