[ZOOKEEPER-2146] BinaryInputArchive readString should check length before allocating memory

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.4.7, 3.5.1, 3.6.0
• Assignee: Hongchao Deng
• Reporter: Hongchao Deng
• Created: 20/Mar/15 23:07
• Updated: 18/Apr/15 00:48
• Resolved: 25/Mar/15 07:40

Description

I recently observed a problem caused by malformed packets. ZK server crashed because of OutOfMemoryError.

The reason is BinaryInputArchive didn't check the length before allocating memory in readString():

  public String readString(String tag) throws IOException {
    	int len = in.readInt();
    	if (len == -1) return null;
    	byte b[] = new byte[len];
        ...

I suggest to add the same check as in readBuffer.