cdr: Missing NULL check and unlock.

* handle_dial_message: Missing a check for NULL peer.
* cdr_generic_register: Missing unlock on allocation failure.

cdr_generic_register is fixed by reordering so the new structure is
allocated and initialized before locking the list.

Change-Id: I5799b99270d1a7a716a555c31ac85f4b00ce8686

main/cdr.c

@@ -2097,7 +2097,12 @@ static void handle_dial_message(void *data, struct stasis_subscription *sub, str
 	if (!peer && !caller) {
 		return;
 	}
-	if (filter_channel_snapshot(peer) || (caller && filter_channel_snapshot(caller))) {
+
+	if (peer && filter_channel_snapshot(peer)) {
+		return;
+	}
+
+	if (caller && filter_channel_snapshot(caller)) {
 		return;
 	}
 
@@ -2871,32 +2876,39 @@ int ast_cdr_backend_unsuspend(const char *name)
 
 static int cdr_generic_register(struct be_list *generic_list, const char *name, const char *desc, ast_cdrbe be)
 {
-	struct cdr_beitem *i = NULL;
+	struct cdr_beitem *i;
+	struct cdr_beitem *cur;
 
-	if (!name)
+	if (!name) {
 		return -1;
+	}
 
 	if (!be) {
 		ast_log(LOG_WARNING, "CDR engine '%s' lacks backend\n", name);
+
+		return -1;
+	}
+
+	i = ast_calloc(1, sizeof(*i));
+	if (!i) {
 		return -1;
 	}
 
+	i->be = be;
+	ast_copy_string(i->name, name, sizeof(i->name));
+	ast_copy_string(i->desc, desc, sizeof(i->desc));
+
 	AST_RWLIST_WRLOCK(generic_list);
-	AST_RWLIST_TRAVERSE(generic_list, i, list) {
-		if (!strcasecmp(name, i->name)) {
+	AST_RWLIST_TRAVERSE(generic_list, cur, list) {
+		if (!strcasecmp(name, cur->name)) {
 			ast_log(LOG_WARNING, "Already have a CDR backend called '%s'\n", name);
 			AST_RWLIST_UNLOCK(generic_list);
+			ast_free(i);
+
 			return -1;
 		}
 	}
 
-	if (!(i = ast_calloc(1, sizeof(*i))))
-		return -1;
-
-	i->be = be;
-	ast_copy_string(i->name, name, sizeof(i->name));
-	ast_copy_string(i->desc, desc, sizeof(i->desc));
-
 	AST_RWLIST_INSERT_HEAD(generic_list, i, list);
 	AST_RWLIST_UNLOCK(generic_list);