diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 149cd4ff6a3bb5cca3621d69c080a15e7baebff7..d29dafce9bb0a38bab42574e1293fd2152c31df7 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -544,7 +544,8 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
  * Optional pinning of buffers is handled at dma-buf attach and detach time in
  * drm_gem_map_attach() and drm_gem_map_detach(). Backing storage itself is
  * handled by drm_gem_map_dma_buf() and drm_gem_unmap_dma_buf(), which relies on
- * &drm_gem_object_funcs.get_sg_table.
+ * &drm_gem_object_funcs.get_sg_table. If &drm_gem_object_funcs.get_sg_table is
+ * unimplemented, exports into another device are rejected.
  *
  * For kernel-internal access there's drm_gem_dmabuf_vmap() and
  * drm_gem_dmabuf_vunmap(). Userspace mmap support is provided by
@@ -583,6 +584,9 @@ int drm_gem_map_attach(struct dma_buf *dma_buf,
 {
 	struct drm_gem_object *obj = dma_buf->priv;
 
+	if (!obj->funcs->get_sg_table)
+		return -ENOSYS;
+
 	return drm_gem_pin(obj);
 }
 EXPORT_SYMBOL(drm_gem_map_attach);