[PATCH v4 3/8] drm/vc4: hdmi: Don't access the connector state in reset if kmalloc fails

Maxime Ripard maxime at cerno.tech
Mon Dec 7 08:39:43 EST 2020

drm_atomic_helper_connector_reset uses kmalloc which, from an API
standpoint, can fail, and thus setting connector->state to NULL.
However, our reset hook then calls drm_atomic_helper_connector_tv_reset
that will access connector->state without checking if it's a valid
pointer or not.

Make sure we don't end up accessing a NULL pointer.

Suggested-by: Dave Stevenson <dave.stevenson at raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime at cerno.tech>
 drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 5a608ed1d75e..112c09873eb4 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -171,7 +171,9 @@ static int vc4_hdmi_connector_get_modes(struct drm_connector *connector)
 static void vc4_hdmi_connector_reset(struct drm_connector *connector)
-	drm_atomic_helper_connector_tv_reset(connector);
+	if (connector->state)
+		drm_atomic_helper_connector_tv_reset(connector);
 static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {

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