Currently pointer plane is being dereferenced on the calls to
drm_atomic_get_old_plane_state and drm_atomic_get_new_plane_state
when assigning old_plane_state and new_plane_state, this could
lead to a null pointer dereference. Fix this by first performing
a null pointer check on plane, then assigning old_plane_state and
new_plance_state and then null pointer checking these.
Fixes: 977697e20b3d ("drm/atomic: Pass the full state to planes atomic disable and update")
Fixes: 37418bf14c13 ("drm: Use state helper instead of the plane state pointer")
Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>
---
drivers/gpu/drm/kmb/kmb_plane.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/kmb/kmb_plane.c b/drivers/gpu/drm/kmb/kmb_plane.c
index 9e0562aa2bcb..07498deba1b6 100644
--- a/drivers/gpu/drm/kmb/kmb_plane.c
+++ b/drivers/gpu/drm/kmb/kmb_plane.c
@@ -341,10 +341,8 @@ static void kmb_plane_set_alpha(struct kmb_drm_private *kmb,
static void kmb_plane_atomic_update(struct drm_plane *plane,
struct drm_atomic_state *state)
{
- struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state,
- plane);
- struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
- plane);
+ struct drm_plane_state *old_plane_state;
+ struct drm_plane_state *new_plane_state;
struct drm_framebuffer *fb;
struct kmb_drm_private *kmb;
unsigned int width;
@@ -359,7 +357,12 @@ static void kmb_plane_atomic_update(struct drm_plane *plane,
static dma_addr_t addr[MAX_SUB_PLANES];
struct disp_cfg *init_disp_cfg;
- if (!plane || !new_plane_state || !old_plane_state)
+ if (!plane)
+ return;
+
+ old_plane_state = drm_atomic_get_old_plane_state(state, plane);
+ new_plane_state = drm_atomic_get_new_plane_state(state, plane);
+ if (!old_plane_state || !new_plane_state)
return;
fb = new_plane_state->fb;
--
2.50.0
