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 Suggested-by: Christian König <[email protected]> Signed-off-by: Jesse Zhang <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c index 87ec46c56a6e..3270ea50bdc7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c @@ -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); -- 2.49.0
