radeon_get_connector_for_encoder() assigns radeon_encoder->enc_priv to mst_enc which is dereferenced later without being checked for NULL beforehand. It is possible for radeon_encoder->enc_priv and therefore mst_enc, to be NULL due to potential lack of memory.
This patch adds a sanity NULL-check to prevent the issue. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 9843ead08f18 ("drm/radeon: add DisplayPort MST support (v2)") Signed-off-by: Nikita Zhandarovich <n.zhandarov...@fintech.ru> --- drivers/gpu/drm/radeon/radeon_encoders.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c index 46549d5179ee..3f68f0af443a 100644 --- a/drivers/gpu/drm/radeon/radeon_encoders.c +++ b/drivers/gpu/drm/radeon/radeon_encoders.c @@ -251,6 +251,9 @@ radeon_get_connector_for_encoder(struct drm_encoder *encoder) continue; mst_enc = radeon_encoder->enc_priv; + if (!mst_enc) + return NULL; + if (mst_enc->connector == radeon_connector->mst_port) return connector; } else if (radeon_encoder->active_device & radeon_connector->devices) -- 2.25.1