High [CVE-2026-74447] fix uint32_t overflow in EOP ring buffer size alignment

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: fix uint32_t overflow in EOP ring buffer size alignment eop_ring_buffer_size in struct queue_properties is a u32.

In kfd_queue_acquire_buffers() the expected EOP buffer size is computed as ALIGN(eop_ring_buffer_size, PAGE_SIZE); ALIGN uses typeof(x), so the addition is done in 32-bit. A user-supplied size of 0xFFFFF001 wraps to 0, causing kfd_queue_buffer_get() to skip its exact-size check (gated on size!= 0) and accept any BO mapped at the address.

On GFX8/GFX9 the MQD cp_hqd_eop_control is then programmed for an 8KB EOP ring backed by a 4KB BO, so CP EOP writes can land past the buffer and fault the GPU.

Cast the operand to u64 so the alignment is computed in 64-bit; the size check in kfd_queue_buffer_get() then rejects the oversized request. (cherry picked from commit ae443117b742c357bfef3a7bddabf76fcf86e9ef) An integer overflow vulnerability exists when aligning the End-of-Pipe (EOP) ring buffer size.

A local attacker could exploit this by providing a specially crafted size that, due to a 32-bit integer overflow, causes the system to bypass buffer size checks. This could lead to writes beyond the intended buffer, potentially causing a Graphics Processing Unit (GPU) fault and resulting in a Denial of Service (DoS).