[patch 3/4] drm/amdgpu: info leak in amdgpu_gem_metadata_ioctl()

[Dan Carpenter]

There is no limit on args->data.data_size_bytes so we could read beyond
the end of the args->data.data[] array.

Reported-by: Ilja Van Sprundel <ivansprundel at ioactive.com>
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 5839fab..dac14de 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -426,6 +426,10 @@ int amdgpu_gem_metadata_ioctl(struct drm_device *dev, void 
*data,
                                           &args->data.data_size_bytes,
                                           &args->data.flags);
        } else if (args->op == AMDGPU_GEM_METADATA_OP_SET_METADATA) {
+               if (args->data.data_size_bytes > sizeof(args->data.data)) {
+                       r = -EINVAL;
+                       goto unreserve;
+               }
                r = amdgpu_bo_set_tiling_flags(robj, args->data.tiling_info);
                if (!r)
                        r = amdgpu_bo_set_metadata(robj, args->data.data,
@@ -433,6 +437,7 @@ int amdgpu_gem_metadata_ioctl(struct drm_device *dev, void 
*data,
                                                   args->data.flags);
        }

+unreserve:
        amdgpu_bo_unreserve(robj);
 out:
        drm_gem_object_unreference_unlocked(gobj);