Amd/sdashmiz/nullstring

[shadidashmiz]

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Technical Details

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[Copilot]

Pull request overview

This PR adjusts HIP no-GPU tests and improves robustness around user object reference handling and fat binary loading, with an additional guard intended to avoid buffer over-reads when inspecting code object magic headers.

Changes:

• Fix NoGpuTst_hipExtStreamGetCUMask to pass a properly sized CU mask array to hipExtStreamGetCUMask instead of a single uint32_t.
• Reorder validation in hipUserObjectRelease so that user object validity is checked before accessing its reference count, avoiding potential dereference of invalid objects.
• Add a minimum-size check before interpreting image_ in FatBinaryInfo::ExtractFatBinaryUsingCOMGR, though the current implementation incorrectly uses strlen on a binary buffer.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
projects/hip-tests/catch/multiproc/hipNoGpuTsts.cc	Updates the no-GPU test for hipExtStreamGetCUMask to allocate a CU mask array of 16 uint32_t entries and pass it correctly to the API.
projects/clr/hipamd/src/hip_graph.cpp	Adjusts the condition in hipUserObjectRelease to validate the user object before comparing referenceCount() against count, reducing the risk of accessing invalid objects.
projects/clr/hipamd/src/hip_fatbin.cpp	Introduces a guard on image_ size before magic string checks in ExtractFatBinaryUsingCOMGR, but currently relies on strlen over a binary buffer, which can itself cause out-of-bounds reads and needs to be reworked to use a real size value.

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[Copilot]

image_ represents an arbitrary binary blob (mapped file or in-memory image), so calling strlen(reinterpret_cast<const char*>(image_)) is undefined behavior: the buffer is not guaranteed to be NUL-terminated and may contain embedded NUL bytes, which can cause out-of-bounds reads or incorrect lengths. To safely enforce the minimum size for the magic string comparisons, use a known size for the mapped region (e.g., ufd_->fsize_ when image_mapped_ is true, or an explicit size tracked alongside image_ for in-memory images) instead of strlen on binary data, and compare that size against kMinMagicSize before calling memcmp-based helpers.

Suggested change

	size_t image_len = strlen(reinterpret_cast<const char*>(image_));
	if (image_len < kMinMagicSize) {
	size_t image_len = 0;
	if (image_mapped_ && ufd_ != nullptr) {
	image_len = ufd_->fsize_;
	}
	if (image_len != 0 && image_len < kMinMagicSize) {