From 5dd86b6e587387b71f01690777d49ae6b240e00a Mon Sep 17 00:00:00 2001 From: Chris Wilson 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 commit 2420489bcb8910188578acc0c11c75445c2e4b92 upstream. 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. Reported-by: Dan Carpenter Fixes: e227330223a7 ("drm/i915: avoid leaking DMA mappings") Signed-off-by: Chris Wilson Cc: Imre Deak Link: http://patchwork.freedesktop.org/patch/msgid/20161114112930.2033-1-chris@chris-wilson.co.uk Reviewed-by: Matthew Auld (cherry picked from commit b17993b7b29612369270567643bcff814f4b3d7f) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_gem.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a77ce9983f69c..b8e3854a1f209 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2540,7 +2540,7 @@ 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 @@ -2583,8 +2583,9 @@ 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); -- 2.47.2