[PATCH] drm/mm: avoid possible null pointer dereference

Heinrich Schuchardt
2016-05-18T20:17:37Z

Do not dereference node before the check if node is NULL.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
drivers/gpu/drm/drm_mm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 04de6fd..cb39f45 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)
--
2.1.4