From: Heinrich Schuchardt Date: Wed, 18 May 2016 20:17:19 +0000 (+0200) Subject: UPSTREAM: drm/mm: avoid possible null pointer dereference X-Git-Tag: firefly_0821_release~943 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=96cee1532e3927cd8ce106ac37d70a4da60163a7;p=firefly-linux-kernel-4.4.55.git UPSTREAM: drm/mm: avoid possible null pointer dereference Do not dereference node before the check if node is NULL. Signed-off-by: Heinrich Schuchardt Reviewed-by: Eric Engestrom Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1463602639-4861-1-git-send-email-xypron.glpk@gmx.de (cherry picked from commit b80d3942329dcd43580adc3f7c0a098515b5feec) Change-Id: I672ce10214e1268a043e6a11268ff400024cc883 Signed-off-by: Mark Yao --- diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 04de6fd88f8c..cb39f45d6a16 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -179,12 +179,14 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_node, int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) { struct drm_mm_node *hole; - u64 end = node->start + node->size; + u64 end; u64 hole_start; u64 hole_end; BUG_ON(node == NULL); + end = node->start + node->size; + /* Find the relevant hole to add our node to */ drm_mm_for_each_hole(hole, mm, hole_start, hole_end) { if (hole_start > node->start || hole_end < end)