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: Christian König <christian.koenig@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Jesse Zhang <jesse.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 688b87d39e)
Cc: stable@vger.kernel.org
This commit is contained in:
Jesse.Zhang
2026-03-12 18:06:17 +08:00
committed by Alex Deucher
parent b49814033c
commit 6270b1a5da

View File

@@ -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);