RFR: 8306461: ObjectInputStream::readObject() should handle negative array sizes without throwing NegativeArraySizeExceptions [v4]

[Roger Riggs]

On Tue, 2 May 2023 13:26:31 GMT, Volker Simonis <simonis at openjdk.org> wrote:

>> This issue was reported by: Yakov Shafranovich ([yakovsh at amazon.com](mailto:yakovsh at amazon.com))
>> 
>> Currently, `ObjectInputStream::readObject()` doesn't explicitly checks for a negative array length in the deserialization stream. Instead it calls `j.l.r.Array::newInstance(..)` with the negative length which results in a `NegativeArraySizeException`. NegativeArraySizeException is an unchecked exception which is neither declared in the signature of `ObjectInputStream::readObject()` nor mentioned in its API specification. It is therefore not obvious for users of `ObjectInputStream::readObject()` that they may have to handle `NegativeArraySizeException`s. It would therefor be better if a negative array length in the deserialization stream would be automatically wrapped in an `InvalidClassException` which is a checked exception (derived from `IOException` via `ObjectStreamException`) and declared in the signature of `ObjectInputStream::readObject()`.
>> 
>> If we do the negative array length check in `ObjectInputStream::readObject()` before filtering, this will then also fix `ObjectInputFilter.FilterInfo::arrayLength()` which is defined as:
>> 
>> Returns:
>> the non-negative number of array elements when deserializing an array of the class, otherwise -1
>> 
>> but currently returns a negative value if the array length is negative.
>
> Volker Simonis has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Throw StreamCorruptedException instead of InvalidClassException and handle negative array size in checkArray() as well

Look good, thanks for fixing checkArray().

test/jdk/java/io/ObjectInputStream/NegativeArraySizeTest.java line 77:

> 75:        byte[] serializedData = baos.toByteArray();
> 76: 
> 77:        // Find the right location to modify, looking for the first instance of TC_ENDBLOCKDATA

The comment should probably mention TC_BLOCKDATA, not TC_END...

-------------

Marked as reviewed by rriggs (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13540#pullrequestreview-1409399775
PR Review Comment: https://git.openjdk.org/jdk/pull/13540#discussion_r1182740104