filter_log_to_metrics: Process validations for range tightly

Signed-off-by: Hiroshi Hatake <hiroshi@chronosphere.io>

Author: cosmo0920

plugins/filter_log_to_metrics/log_to_metrics.c

@@ -181,6 +181,13 @@ static int prepare_label_runtime(struct log_to_metrics_ctx *ctx)
         flb_free(ctx->label_accessors);
         ctx->label_accessors = NULL;
     }
+    if (ctx->label_ras) {
+        for (i = 0; i < ctx->label_counter; i++) {
+            flb_ra_destroy(ctx->label_ras[i]);
+        }
+        flb_free(ctx->label_ras);
+        ctx->label_ras = NULL;
+    }
     return -1;
 }
 
@@ -403,7 +410,7 @@ static int set_labels(struct log_to_metrics_ctx *ctx,
     ctx->label_keys = flb_calloc(ctx->label_counter, sizeof(char *));
     if (!ctx->label_keys) {
         flb_errno();
-        return -1;
+        goto error;
     }
 
     ctx->label_accessors = flb_calloc(ctx->label_counter, sizeof(char *));
@@ -434,12 +441,12 @@ static int set_labels(struct log_to_metrics_ctx *ctx,
     mk_list_foreach(head, &f_ins->properties) {
         kv = mk_list_entry(head, struct flb_kv, _head);
 
-        if (counter > ctx->label_counter) {
-            flb_plg_error(ctx->ins, "internal label counter overflow");
-            return -1;
-        }
-
         if (strcasecmp(kv->key, "label_field") == 0) {
+            if (counter >= ctx->label_counter) {
+                flb_plg_error(ctx->ins, "internal label counter overflow");
+                goto error;
+            }
+
             /* name and accessor are the same string */
             ctx->label_keys[counter] = flb_strdup(kv->val);
             if (!ctx->label_keys[counter]) {
@@ -454,11 +461,15 @@ static int set_labels(struct log_to_metrics_ctx *ctx,
             counter++;
         }
         else if (strcasecmp(kv->key, "add_label") == 0) {
+            if (counter >= ctx->label_counter) {
+                flb_plg_error(ctx->ins, "internal label counter overflow");
+                goto error;
+            }
             split = flb_utils_split(kv->val, ' ', 1);
             if (mk_list_size(split) != 2) {
                 flb_plg_error(ctx->ins, "invalid label, expected name and key");
                 flb_utils_split_free(split);
-                return -1;
+                goto error;
             }
 
             sentry = mk_list_entry_first(split, struct flb_split_entry, _head);