4.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: Chris Wilson <[email protected]> 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 <[email protected]> Fixes: e227330223a7 ("drm/i915: avoid leaking DMA mappings") Signed-off-by: Chris Wilson <[email protected]> Cc: Imre Deak <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] Reviewed-by: Matthew Auld <[email protected]> (cherry picked from commit b17993b7b29612369270567643bcff814f4b3d7f) Signed-off-by: Jani Nikula <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/i915/i915_gem.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- 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 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 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);
