CVE-2026-74447: drm/amdkfd: fix uint32_t overflow in EOP ring buffer size alignment

In the Linux kernel, the following vulnerability has been resolved:

drm/amdkfd: fix uint32t overflow in EOP ring buffer size alignment

eopringbuffersize in struct queueproperties is a u32. In kfdqueueacquirebuffers() the expected EOP buffer size is computed as ALIGN(eopringbuffersize, PAGESIZE); ALIGN uses typeof(x), so the addition is done in 32-bit. A user-supplied size of 0xFFFFF001 wraps to 0, causing kfdqueuebufferget() to skip its exact-size check (gated on size != 0) and accept any BO mapped at the address. On GFX8/GFX9 the MQD cphqdeopcontrol 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 kfdqueuebufferget() then rejects the oversized request.

(cherry picked from commit ae443117b742c357bfef3a7bddabf76fcf86e9ef)