drm/amdkfd: Reject zero-sized AQL queue allocations after size halving

KFD_IOC_ALLOC_MEMORY_OF_GPU with flag
KFD_IOC_ALLOC_MEM_FLAGS_AQL_QUEUE_MEM and size=1 triggers the AQL
wraparound workaround (size >>= 1), reducing size to 0. The resulting
zero passes through PAGE_ALIGN(0) = 0 without validation, bypassing the
per-process VRAM quota check in reserve_mem_limit()
(vram_used + 0 > vram_available is always false).

The fix adds post-halving zero-size validation in the primary
allocation path (amdgpu_amdkfd_gpuvm.c). The check happens after size
halving but before reserve_mem_limit(), and uses err_alignment_size
error path to properly clean up the allocated kgd_mem structure and
mutex.

Cc: stable@vger.kernel.org
Signed-off-by: Sunday Clement <Sunday.Clement@amd.com>
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions