FAILED: patch "[PATCH] drm/i915: Don't touch NULL sg on" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Chris Wilson <[email protected]>
Date: Mon, 14 Nov 2016 11:29:30 +0000
Subject: [PATCH] drm/i915: Don't touch NULL sg on
i915_gem_object_get_pages_gtt() error

On the DMA mapping error path, sg may be NULL (it has already been marked as the last scatterlist entry), and we should avoid dereferencing it again.

index 91ab7e9d6d2e..00eb4814b913 100644
@@ -2268,7 +2268,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 			page = shmem_read_mapping_page(mapping, i);
 			if (IS_ERR(page)) {
 				ret = PTR_ERR(page);
-				goto err_pages;
+				goto err_sg;
 			}
 		}
 #ifdef CONFIG_SWIOTLB

@@ -2311,8 +2311,9 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 
 	return 0;
 
-err_pages:
+err_sg:
 	sg_mark_end(sg);
+err_pages:
 	for_each_sgt_page(page, sgt_iter, st)
 		put_page(page);
 	sg_free_table(st);