Review Request for JMC-6621 - Handle event size 0

[Henrik Dafgård]

Hi all,

Should JMC attempt to parse a recording with an event size of 0 (this
should not be possible) it will currently enter an infinite loop. The patch
outlined below simply adds a check for size 0 and then throws a
CouldNotLoadRecordingException if that is the case.

diff -r b153474a15a6
core/org.openjdk.jmc.flightrecorder/src/main/java/org/openjdk/jmc/flightrecorder/internal/parser/v1/ChunkLoaderV1.java
---
a/core/org.openjdk.jmc.flightrecorder/src/main/java/org/openjdk/jmc/flightrecorder/internal/parser/v1/ChunkLoaderV1.java
Fri Oct 25 15:48:20 2019 +0200
+++
b/core/org.openjdk.jmc.flightrecorder/src/main/java/org/openjdk/jmc/flightrecorder/internal/parser/v1/ChunkLoaderV1.java
Thu Oct 31 15:00:27 2019 +0100
@@ -84,6 +84,9 @@
  input.seek(index);
  int size = input.readInt();
  long type = input.readLong();
+ if (size == 0) {
+ throw new CouldNotLoadRecordingException("Found event with invalid size
(0)");
+ }
  if (type != CONSTANT_POOL_EVENT_TYPE && type !=
ChunkMetadata.METADATA_EVENT_TYPE) {
  manager.readEvent(type, input);
  }


Cheers,
Henrik Dafgård