Commit 6270b1a5 authored by Jesse.Zhang's avatar Jesse.Zhang Committed by Alex Deucher
Browse files

drm/amdgpu: Limit BO list entry count to prevent resource exhaustion 



Userspace can pass an arbitrary number of BO list entries via the
bo_number field. Although the previous multiplication overflow check
prevents out-of-bounds allocation, a large number of entries could still
cause excessive memory allocation (up to potentially gigabytes) and
unnecessarily long list processing times.

Introduce a hard limit of 128k entries per BO list, which is more than
sufficient for any realistic use case (e.g., a single list containing all
buffers in a large scene). This prevents memory exhaustion attacks and
ensures predictable performance.

Return -EINVAL if the requested entry count exceeds the limit

Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Suggested-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarJesse Zhang <jesse.zhang@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 688b87d3)
Cc: stable@vger.kernel.org
parent b4981403

drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

+4 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 


#define AMDGPU_BO_LIST_MAX_PRIORITY	32u

#define AMDGPU_BO_LIST_NUM_BUCKETS	(AMDGPU_BO_LIST_MAX_PRIORITY + 1)

#define AMDGPU_BO_LIST_MAX_ENTRIES	(128 * 1024)



static void amdgpu_bo_list_free_rcu(struct rcu_head *rcu)

{
@@ -188,6 +189,9 @@ int amdgpu_bo_create_list_entry_array(struct drm_amdgpu_bo_list_in *in, 
	const uint32_t bo_number = in->bo_number;

	struct drm_amdgpu_bo_list_entry *info;



	if (bo_number > AMDGPU_BO_LIST_MAX_ENTRIES)

		return -EINVAL;



	/* copy the handle array from userspace to a kernel buffer */

	if (likely(info_size == bo_info_size)) {

		info = vmemdup_array_user(uptr, bo_number, info_size);