Fix use before null check

src/sn_utils.c

@@ -1348,9 +1348,11 @@ static int re_register_and_purge_supernodes (n2n_sn_t *sss, struct sn_community
         }
 
         // purge long-time-not-seen supernodes
+        if (comm) {
             purge_expired_nodes(&(comm->edges), sss->sock, &sss->tcp_connections, p_last_re_reg_and_purge,
                                 RE_REG_AND_PURGE_FREQUENCY, LAST_SEEN_SN_INACTIVE);
         }
+    }
 
     if(comm != NULL) {
         HASH_ITER(hh,comm->edges,peer,tmp) {

src/transform_aes.c

@@ -41,10 +41,9 @@ static int transop_deinit_aes (n2n_trans_op_t *arg) {
 
     transop_aes_t *priv = (transop_aes_t *)arg->priv;
 
+    if(priv)
         if(priv->ctx)
             aes_deinit(priv->ctx);
-
-    if(priv)
         free(priv);
 
     return 0;

src/transform_cc20.c

@@ -33,10 +33,9 @@ static int transop_deinit_cc20 (n2n_trans_op_t *arg) {
 
     transop_cc20_t *priv = (transop_cc20_t *)arg->priv;
 
+    if(priv)
         if(priv->ctx)
             cc20_deinit(priv->ctx);
-
-    if(priv)
         free(priv);
 
     return 0;

src/transform_speck.c

@@ -33,10 +33,9 @@ static int transop_deinit_speck (n2n_trans_op_t *arg) {
 
     transop_speck_t *priv = (transop_speck_t *)arg->priv;
 
+    if(priv)
         if(priv->ctx)
             speck_deinit(priv->ctx);
-
-    if(priv)
         free(priv);
 
     return 0;

src/transform_tf.c

@@ -41,10 +41,9 @@ static int transop_deinit_tf (n2n_trans_op_t *arg) {
 
     transop_tf_t *priv = (transop_tf_t *)arg->priv;
 
+    if(priv)
         if(priv->ctx)
             tf_deinit(priv->ctx);
-
-    if(priv)
         free(priv);
 
     return 0;