out_stackdriver: fix multiple memory leaks and potential corruption

- Update fetch_metadata to use flb_sds_t * to handle sds reallocation correctly

- Use temporary variable in fetch_metadata to avoid leaking original SDS on failure

- Fix error handling in fetch_metadata when flb_sds_copy fails

- Fix memory leaks in stackdriver.c by destroying rval and http_request in failure paths

- Fix memory leak in stackdriver_conf.c by destroying project_id before overwriting it

Signed-off-by: Tim Bai <timbai@google.com>

Author: baizhenyu

plugins/out_stackdriver/gce_metadata.c

@@ -33,7 +33,7 @@
 
 static int fetch_metadata(struct flb_stackdriver *ctx,
                           struct flb_upstream *upstream, char *uri,
-                          char *payload)
+                          flb_sds_t *payload)
 {
     int ret;
     int ret_code;
@@ -44,21 +44,30 @@ static int fetch_metadata(struct flb_stackdriver *ctx,
     /* If runtime test mode is enabled, add test data */
     if (ctx->ins->test_mode == FLB_TRUE) {
         if (strcmp(uri, FLB_STD_METADATA_PROJECT_ID_URI) == 0) {
-            if (!flb_sds_cat(payload, "fluent-bit-test", 15)) {
+            flb_sds_t tmp;
+            tmp = flb_sds_cat(*payload, "fluent-bit-test", 15);
+            if (!tmp) {
                 return -1;
             }
+            *payload = tmp;
             return 0;
         }
         else if (strcmp(uri, FLB_STD_METADATA_ZONE_URI) == 0) {
-            if (!flb_sds_cat(payload, "projects/0123456789/zones/fluent", 32)) {
+            flb_sds_t tmp;
+            tmp = flb_sds_cat(*payload, "projects/0123456789/zones/fluent", 32);
+            if (!tmp) {
                 return -1;
             }
+            *payload = tmp;
             return 0;
         }
         else if (strcmp(uri, FLB_STD_METADATA_INSTANCE_ID_URI) == 0) {
-            if (!flb_sds_cat(payload, "333222111", 9)) {
+            flb_sds_t tmp;
+            tmp = flb_sds_cat(*payload, "333222111", 9);
+            if (!tmp) {
                 return -1;
             }
+            *payload = tmp;
             return 0;
         }
         return -1;
@@ -93,8 +102,15 @@ static int fetch_metadata(struct flb_stackdriver *ctx,
         /* The request was issued successfully, validate the 'error' field */
         flb_plg_debug(ctx->ins, "HTTP Status=%i", c->resp.status);
         if (c->resp.status == 200) {
-            ret_code = 0;
-            flb_sds_copy(payload, c->resp.payload, c->resp.payload_size);
+            flb_sds_t tmp;
+            tmp = flb_sds_copy(*payload, c->resp.payload, c->resp.payload_size);
+            if (!tmp) {
+                ret_code = -1;
+            }
+            else {
+                *payload = tmp;
+                ret_code = 0;
+            }
         }
         else {
             if (c->resp.payload_size > 0) {
@@ -150,7 +166,7 @@ int gce_metadata_read_token(struct flb_stackdriver *ctx)
     }
     uri = tmp;
 
-    ret = fetch_metadata(ctx, ctx->metadata_u, uri, payload);
+    ret = fetch_metadata(ctx, ctx->metadata_u, uri, &payload);
     if (ret != 0) {
         flb_plg_error(ctx->ins, "can't fetch token from the metadata server");
         flb_sds_destroy(payload);
@@ -180,7 +196,7 @@ int gce_metadata_read_zone(struct flb_stackdriver *ctx)
     flb_sds_t zone = NULL;
 
     ret = fetch_metadata(ctx, ctx->metadata_u, FLB_STD_METADATA_ZONE_URI,
-                         payload);
+                         &payload);
     if (ret != 0) {
         flb_plg_error(ctx->ins, "can't fetch zone from the metadata server");
         flb_sds_destroy(payload);
@@ -226,7 +242,7 @@ int gce_metadata_read_project_id(struct flb_stackdriver *ctx)
     flb_sds_t payload = flb_sds_create_size(4096);
 
     ret = fetch_metadata(ctx, ctx->metadata_u,
-                         FLB_STD_METADATA_PROJECT_ID_URI, payload);
+                         FLB_STD_METADATA_PROJECT_ID_URI, &payload);
     if (ret != 0) {
         flb_plg_error(ctx->ins, "can't fetch project id from the metadata server");
         flb_sds_destroy(payload);
@@ -243,7 +259,7 @@ int gce_metadata_read_instance_id(struct flb_stackdriver *ctx)
     flb_sds_t payload = flb_sds_create_size(4096);
 
     ret = fetch_metadata(ctx, ctx->metadata_u,
-                         FLB_STD_METADATA_INSTANCE_ID_URI, payload);
+                         FLB_STD_METADATA_INSTANCE_ID_URI, &payload);
     if (ret != 0) {
         flb_plg_error(ctx->ins, "can't fetch instance id from the metadata server");
         flb_sds_destroy(payload);

plugins/out_stackdriver/stackdriver.c

@@ -1164,6 +1164,9 @@ static int pack_resource_labels(struct flb_stackdriver *ctx,
                 } else {
                     flb_plg_warn(ctx->ins, "failed to find a corresponding entry for "
                         "resource label entry [%s=%s]", label_kv->key, label_kv->val);
+                    if (rval) {
+                        flb_ra_key_value_destroy(rval);
+                    }
                 }
                 flb_ra_destroy(ra);
             } else {
@@ -2510,6 +2513,8 @@ static flb_sds_t stackdriver_format(struct flb_stackdriver *ctx,
                 flb_sds_destroy(log_name);
             }
 
+            destroy_http_request(&http_request);
+
             flb_log_event_decoder_destroy(&log_decoder);
             msgpack_sbuffer_destroy(&mp_sbuf);
 

plugins/out_stackdriver/stackdriver_conf.c

@@ -134,6 +134,9 @@ static int read_credentials_file(const char *cred_file, struct flb_stackdriver *
             ctx->creds->type = flb_sds_create_len(val, val_len);
         }
         else if (key_cmp(key, key_len, "project_id") == 0) {
+            if (ctx->project_id) {
+                flb_sds_destroy(ctx->project_id);
+            }
             ctx->project_id = flb_sds_create_len(val, val_len);
         }
         else if (key_cmp(key, key_len, "private_key_id") == 0) {