Repository navigation
mesa: Clamp a buffer descriptor's range to its buffer (#128) - #141
Merged
Merged
Conversation
Codex Review SummaryThis comment shows the latest Codex review activity on this pull request.
ℹ️ About Codex in GitHubYour team has set up Codex to review pull requests in this repo. Reviews are triggered when you
Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings. |
DOOM (2016) writes uniform buffer descriptors with a 64 KB range on smaller buffers, which aborted on an assertion in Mesa; without it the reads would have gone past the buffer into other memory. Mesa patch 0086 clamps the range, so they are out of bounds like any other. tests/mac/vk-ubo-range-past-end.sh, findings #58. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KCKKoKPBaWBVBojHFrLgQ9
Merged
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Stacked on #140.
Once depth bounds are reported, DOOM (2016) aborts on a Mesa assertion,
range + offset <= buffer->size. It writes uniform buffer descriptors with a 64 KB range on buffers of 49,152 and 65,520 bytes (#128). That is invalid Vulkan, and our Mesa is built with assertions on.Turning the assertions off wouldn't be enough. With the range kept as given, KosmicKrisp's bounds checks let the shader read past the buffer into whatever memory follows it.
Mesa patch 0086 clamps a buffer descriptor's range (and a transform feedback buffer's) to the end of its buffer. Reads past the end are then out of bounds like any other: zero with robust access. Valid ranges are unchanged. Findings #58.
Testing:
tests/mac/vk-ubo-range-past-end.shwrites descriptors the way DOOM does, plain and dynamic, with a marker-filled buffer right after.