vulkan: Use 64-bit arithmetic for scaled readback buffer sizes#149
Merged
Conversation
Contributor
Author
|
Hi @jmacnak PTAL. I think I will change the API structure a lot, so I didn't add unit tests for it. |
jmacnak
requested changes
Jun 23, 2026
readColorBufferPixelsScaledCpu() and ResizeRGBAImage() computed pixel buffer sizes and indices as 'width * height * bpp' in 32-bit int before widening to the uint64_t/size_t they are stored in. The dimensions here come from the host screenshot path rather than the guest, so this is a robustness fix rather than a guest-reachable overflow, but the mixed arithmetic is inconsistent with the explicit (uint64_t) cast already used a few lines up at the simple-readback size computation. Perform these multiplications in 64-bit: cast the scaled output size and the resize allocation to 64-bit, and widen ResizeRGBAImage's pixel index helper and index variables to int64_t so the index math cannot overflow independently of the allocation. Test: bazel build //host/vulkan:gfxstream_vulkan_server Change-Id: I71c06bf932ad5ee598b907bfb5daf46dde69f9c0
utzcoz
force-pushed
the
64-bit-arithmetic
branch
from
ce859cb to
904aba6
Compare
Contributor
Author
|
@jmacnak Updated. PTAL. |
jmacnak
approved these changes
Jun 23, 2026
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
3 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
readColorBufferPixelsScaledCpu() and ResizeRGBAImage() computed pixel buffer sizes and indices as 'width * height * bpp' in 32-bit int before widening to the uint64_t/size_t they are stored in. The dimensions here come from the host screenshot path rather than the guest, so this is a robustness fix rather than a guest-reachable overflow, but the mixed arithmetic is inconsistent with the explicit (uint64_t) cast already used a few lines up at the simple-readback size computation.
Perform these multiplications in 64-bit: cast the scaled output size and the resize allocation to 64-bit, and widen ResizeRGBAImage's pixel index helper and index variables to int64_t so the index math cannot overflow independently of the allocation.
Test: bazel build //host/vulkan:gfxstream_vulkan_server