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: NDan Carpenter <dan.carpenter@oracle.com>
Fixes: e2273302 ("drm/i915: avoid leaking DMA mappings")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Cc: stable@vger.kernel.org
Link: http://patchwork.freedesktop.org/patch/msgid/20161114112930.2033-1-chris@chris-wilson.co.ukReviewed-by: NMatthew Auld <matthew.auld@intel.com>
(cherry picked from commit b17993b7)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>