RFR: 8306461: ObjectInputStream::readObject() should handle negative array sizes without throwing NegativeArraySizeExceptions [v2]

[Aleksey Shipilev]

On Mon, 24 Apr 2023 14:41:58 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:
> 
>   Addresed review comments of @turbanoff, @shipilev and @RogerRiggs

Test questions:

test/jdk/java/io/ObjectInputStream/NegativeArraySizeTest.java line 88:

> 86:         } catch (ObjectStreamException ose) {
> 87:             // OK, because a NegativeArraySizeException should be converted into a ObjectStreamException
> 88:             if ("Array length is negative".equals(ose.getMessage())) {

This feels like `!equals`, i.e. throw exception when the message is *not* "Array length is negative"?

test/jdk/java/io/ObjectInputStream/NegativeArraySizeTest.java line 104:

> 102:             }
> 103:             // OK, because a NegativeArraySizeException should be converted into a ObjectStreamException *before* filtering
> 104:             if ("Array length is negative".equals(ose.getMessage())) {

Same as above.

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

Changes requested by shade (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13540#pullrequestreview-1398354018
PR Review Comment: https://git.openjdk.org/jdk/pull/13540#discussion_r1175496936
PR Review Comment: https://git.openjdk.org/jdk/pull/13540#discussion_r1175497098