kali834x opened a new pull request, #808: URL: https://github.com/apache/commons-compress/pull/808
readPackInfo reads the numPackStreams field but only allocates and fills archive.packSizes inside the optional kSize property block, so a crafted 7z whose kPackInfo declares a non-zero packed stream count and omits kSize leaves packSizes as the default empty array. the sanity pass does not catch it: sanityCheckPackInfo sets numberOfPackedStreams from the declared count whether or not kSize is present, so the count comparison in sanityCheckUnpackInfo still matches. calculateStreamMap then builds a zero-length packStreamOffsets while folderFirstPackStreamIndex[0] stays 0, and the first getNextEntry indexes archive.packSizes[0] in buildDecoderStack and packStreamOffsets[0] in reopenFolderInputStream, throwing ArrayIndexOutOfBoundsException out of getNextEntry which only declares IOException. require packSizes.length to equal the declared count in readPackInfo, mirroring the isEmpty(packSizes) guard the encoded-header path already has; an archive that legitimately declares zero packed streams still passes since 0 == 0. - [x] Read the [contribution guidelines](CONTRIBUTING.md) for this project. - [ ] Read the [ASF Generative Tooling Guidance](https://www.apache.org/legal/generative-tooling.html) if you use Artificial Intelligence (AI). - [ ] I used AI to create any part of, or all of, this pull request. Which AI tool was used to create this pull request, and to what extent did it contribute? - [x] Run a successful build using the default [Maven](https://maven.apache.org/) goal with `mvn`; that's `mvn` on the command line by itself. - [x] Write unit tests that match behavioral changes, where the tests fail if the changes to the runtime are not applied. This may not always be possible, but it is a best practice. - [x] Write a pull request description that is detailed enough to understand what the pull request does, how, and why. - [x] Each commit in the pull request should have a meaningful subject line and body. Note that a maintainer may squash commits during the merge process. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
