amdgpu_dm_connector_atomic_check() checks whether the old or new
connector state returned by the atomic helpers is NULL before using
those pointers.
However, new_con_state is already dereferenced while initializing crtc,
before the NULL check is reached. If
drm_atomic_get_new_connector_state() returns NULL, the function can
dereference the NULL pointer before the WARN_ON() check can handle it.
Declare crtc first and initialize it only after the NULL check has
succeeded.
Fixes: 1e5e8d672fec ("drm/amd/display: Avoid a NULL pointer dereference")
Signed-off-by: Guangshuo Li <[email protected]>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
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 d3a8d681227a..7b040fd7e3fb 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -8640,13 +8640,14 @@ amdgpu_dm_connector_atomic_check(struct drm_connector
*conn,
drm_atomic_get_new_connector_state(state, conn);
struct drm_connector_state *old_con_state =
drm_atomic_get_old_connector_state(state, conn);
- struct drm_crtc *crtc = new_con_state->crtc;
+ struct drm_crtc *crtc;
struct drm_crtc_state *new_crtc_state;
struct amdgpu_dm_connector *aconn = to_amdgpu_dm_connector(conn);
int ret;
if (WARN_ON(unlikely(!old_con_state || !new_con_state)))
return -EINVAL;
+ crtc = new_con_state->crtc;
trace_amdgpu_dm_connector_atomic_check(new_con_state);
--
2.43.0
