Closes confluentinc#4649

emasab · Jul 25, 2024 · 96d1055 · 96d1055
1 parent 26841c2
commit 96d1055
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,25 @@
+# librdkafka v2.5.1 (can vary)
+
+librdkafka v2.5.1 is a maintenance release.
+
+* Fix for retrieving offset commit metadata when it contains
+  zeros and configured with `strndup` (#4795)
+
+
+## Fixes
+
+### Consumer fixes
+
+* Issues: #4649.
+  When retrieving offset metadata, if the binary value contained zeros
+  and librdkafka was configured with `strndup`, part of
+  the buffer after first zero contained uninitialized data
+  instead of rest of metadata. Solved by avoiding to use
+  `strndup` for copying metadata.
+  Happens since: 0.9.0 (#4795).
+
+
+
 # librdkafka v2.5.0
 
 librdkafka v2.5.0 is a feature release.

diff --git a/src/rdkafka_request.c b/src/rdkafka_request.c
@@ -1289,9 +1289,15 @@ rd_kafka_handle_OffsetFetch(rd_kafka_t *rk,
                                 rktpar->metadata      = NULL;
                                 rktpar->metadata_size = 0;
                         } else {
-                                rktpar->metadata = RD_KAFKAP_STR_DUP(&metadata);
-                                rktpar->metadata_size =
-                                    RD_KAFKAP_STR_LEN(&metadata);
+                                /* It cannot use strndup because
+                                 * it stops at first 0 occurrence. */
+                                size_t len = RD_KAFKAP_STR_LEN(&metadata);
+                                rktpar->metadata_size = len;
+                                unsigned char *metadata_bytes =
+                                    rd_malloc(len + 1);
+                                rktpar->metadata = metadata_bytes;
+                                memcpy(rktpar->metadata, metadata.str, len);
+                                metadata_bytes[len] = '\0';
                         }
 
                         /* Loose ref from get_toppar() */