drm/amdgpu: validate user GEM object size (c4a32b26) · Commits · 戴 / test

When creating frame buffer, userspace may request to attach to a previously allocated GEM object that is smaller than what GPU requires. Validation must be done to prevent out-of-bound DMA, otherwise it could be exploited to reveal sensitive data. This fix is not done in a common code path because individual driver might have different requirement. Cc: stable@vger.kernel.org # v4.2+ Reviewed-by:

Michel Dänzer <michel.daenzer@amd.com> Signed-off-by:

Yu Zhao <yuzhao@google.com> Signed-off-by:

Alex Deucher <alexander.deucher@amd.com>

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

+8 −0

Original line number	Diff line number	Diff line
		@@ -531,6 +531,7 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev,
		struct drm_gem_object *obj;
		struct amdgpu_framebuffer *amdgpu_fb;
		int ret;
		int height;
		struct amdgpu_device *adev = dev->dev_private;
		int cpp = drm_format_plane_cpp(mode_cmd->pixel_format, 0);
		int pitch = mode_cmd->pitches[0] / cpp;
		@@ -555,6 +556,13 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev,
		return ERR_PTR(-EINVAL);
		}

		height = ALIGN(mode_cmd->height, 8);
		if (obj->size < pitch * height) {
		DRM_DEBUG_KMS("Invalid GEM size: expecting >= %d but got %zu\n",
		pitch * height, obj->size);
		return ERR_PTR(-EINVAL);
		}

		amdgpu_fb = kzalloc(sizeof(*amdgpu_fb), GFP_KERNEL);
		if (amdgpu_fb == NULL) {
		drm_gem_object_put_unlocked(obj);

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