in_systemd: Don't insert rows if flb_sqldb_query fails

This can potentially cause an issue where a new row is
inserted into in_systemd_cursor table and in_systemd_cursor
table can now have more than one row. Once multiple rows
exist in the table, this then causes a memory leak as
strdup will be called for each row to set qs.cursor in
cb_cursor_check, however qs.cursor will only be freed once.

Signed-off-by: Daniel Lenar <[email protected]>

Author: danlenar

plugins/in_systemd/systemd_db.c

@@ -137,6 +137,10 @@ int flb_systemd_db_init_cursor(struct flb_systemd_config *ctx, const char *curso
     ret = flb_sqldb_query(ctx->db,
                           SQL_GET_CURSOR, cb_cursor_check, &qs);
 
+    if (ret != FLB_OK) {
+        return -1;
+    }
+
     if (qs.rows == 0) {
         /* Register the cursor */
         snprintf(query, sizeof(query) - 1,