From: William Palacek Date: Mon, 20 Jul 2026 16:51:34 +0000 (-0400) Subject: drm/amdkfd: fix uint32_t overflow in EOP ring buffer size alignment X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=83463a96ea3c7d8ae636a4d6a0ba63c9ce410724;p=thirdparty%2Flinux.git 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. Fixes: 42ea9cf2f16b ("drm/amdkfd: Relax size checking during queue buffer get") Signed-off-by: William Palacek Reviewed-by: Alysa Liu Signed-off-by: Alex Deucher (cherry picked from commit ae443117b742c357bfef3a7bddabf76fcf86e9ef) Cc: stable@vger.kernel.org --- diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_queue.c b/drivers/gpu/drm/amd/amdkfd/kfd_queue.c index 98a5512b701b..b249e7d1af48 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_queue.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_queue.c @@ -288,7 +288,7 @@ int kfd_queue_acquire_buffers(struct kfd_process_device *pdd, struct queue_prope } err = kfd_queue_buffer_get(vm, (void *)properties->eop_ring_buffer_address, &properties->eop_buf_bo, - ALIGN(properties->eop_ring_buffer_size, PAGE_SIZE)); + ALIGN((u64)properties->eop_ring_buffer_size, PAGE_SIZE)); if (err) goto out_err_unreserve; }