The function amdgpu_dm_crtc_mem_type_changed was dereferencing pointers
returned by drm_atomic_get_plane_state without checking for errors. This
could lead to undefined behavior if the function returns an error pointer.
This commit adds checks using IS_ERR to ensure that new_plane_state and
old_plane_state are valid before dereferencing them.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:11486 amdgpu_dm_crtc_mem_type_changed()
error: 'new_plane_state' dereferencing possible ERR_PTR()
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c
11475 static bool amdgpu_dm_crtc_mem_type_changed(struct drm_device *dev,
11476 struct drm_atomic_state *state,
11477 struct drm_crtc_state *crtc_state)
11478 {
11479 struct drm_plane *plane;
11480 struct drm_plane_state *new_plane_state, *old_plane_state;
11481
11482 drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
11483 new_plane_state = drm_atomic_get_plane_state(state, plane);
11484 old_plane_state = drm_atomic_get_plane_state(state, plane);
^^^^^^^^^^^^^^^^^^^^^^^^^^ These functions can fail.
11485
--> 11486 if (old_plane_state->fb && new_plane_state->fb &&
11487 get_mem_type(old_plane_state->fb) != get_mem_type(new_plane_state->fb))
11488 return true;
11489 }
11490
11491 return false;
11492 }
Fixes: 1079bd90c55b ("drm/amd/display: Do not elevate mem_type change to full update")
Cc: Leo Li <sunpeng.li@xxxxxxx>
Cc: Tom Chung <chiahsuan.chung@xxxxxxx>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Cc: Roman Li <roman.li@xxxxxxx>
Cc: Alex Hung <alex.hung@xxxxxxx>
Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Cc: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index fe75fbced027..f3f319238763 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -11523,6 +11523,11 @@ static bool amdgpu_dm_crtc_mem_type_changed(struct drm_device *dev,
new_plane_state = drm_atomic_get_plane_state(state, plane);
old_plane_state = drm_atomic_get_plane_state(state, plane);
+ if (IS_ERR(new_plane_state) || IS_ERR(old_plane_state)) {
+ DRM_ERROR("Failed to get plane state for plane %s\n", plane->name);
+ return false;
+ }
+
if (old_plane_state->fb && new_plane_state->fb &&
get_mem_type(old_plane_state->fb) != get_mem_type(new_plane_state->fb))
return true;
--
2.34.1
