Link: https://narkive.com/tsmcN7nY.2 

--- a/sendmail/map.c
+++ b/sendmail/map.c
@@ -3042,7 +3042,7 @@
 	char **av;
 	int *statp;
 {
-	char *data;
+	char *data, *result;
 	struct cdb *cdbmap;
 	unsigned int klen, dlen;
 	int st, fd;
@@ -3050,6 +3050,7 @@
 	char buf[MAXPATHLEN];
 
 	data = NULL;
+	result = NULL;
 	cdbmap = map->map_db1;
 	if (tTd(38, 20))
 		sm_dprintf("cdb_map_lookup(%s, %s)\n", map->map_mname, name);
@@ -3136,14 +3137,22 @@
 	else
 	{
 		dlen = cdb_datalen(cdbmap);
-		data = malloc(dlen + 1);
+		data = (char *) sm_malloc(dlen + 1);
+		if (NULL == data)
+		{
+			*statp = EX_TEMPFAIL;
+			return NULL;
+		}
 		cdb_read(cdbmap, data, dlen, cdb_datapos(cdbmap));
 		data[dlen] = '\0';
 	}
 	if (bitset(MF_MATCHONLY, map->map_mflags))
-		return map_rewrite(map, name, strlen(name), NULL);
+		result = map_rewrite(map, name, strlen(name), NULL);
 	else
-		return map_rewrite(map, data, dlen, av);
+		result = map_rewrite(map, data, dlen, av);
+
+	SM_FREE(data);
+	return result;
 }
 
 /*