Add grid dimension validation

[apsonawane]

This pull request adds important validation and safety checks to the QwenVisionPipeline::CalculateWindowIndex function in src/models/qwen_vl_vision.cpp. The changes are focused on improving robustness by validating input dimensions and preventing integer overflows during memory allocation.

Input Validation and Safety Improvements:

• Added checks to ensure that all grid dimensions (grid_t, grid_h, grid_w) are positive; throws an exception if not.
• Added upper bounds for grid dimensions and total allocation size to prevent integer overflow and excessive memory usage (limits each dimension and the total number of elements to ~1 billion). Throws exceptions if exceeded.
• Refactored allocation and indexing logic to use the new validated and padded dimensions, improving clarity and safety. [1] [2]

[Copilot]

Pull request overview

This PR strengthens robustness in the Qwen VL vision pipeline by adding validation around QwenVisionPipeline::CalculateWindowIndex, which computes window reordering indices from image_grid_thw-derived dimensions.

Changes:

• Added input validation for non-positive grid dimensions.
• Introduced upper bounds intended to prevent excessive allocations / overflows.
• Refactored allocation and indexing to use precomputed padded dimensions and a single alloc_size.

[Copilot]

Pull request overview

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