target/linux/bcm27xx/patches-5.10/950-0413-drm-vc4-hdmi-Don-t-access-the-connector-state-in-res.patch

   1 From e1b4f5c3970e14abe197f328077b348b4969e68f Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Tue, 15 Dec 2020 16:42:38 +0100
   4 Subject: [PATCH] drm/vc4: hdmi: Don't access the connector state in
   5  reset if kmalloc fails
   6
   7 drm_atomic_helper_connector_reset uses kmalloc which, from an API
   8 standpoint, can fail, and thus setting connector->state to NULL.
   9 However, our reset hook then calls drm_atomic_helper_connector_tv_reset
  10 that will access connector->state without checking if it's a valid
  11 pointer or not.
  12
  13 Make sure we don't end up accessing a NULL pointer.
  14
  15 Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
  16 Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  17 Suggested-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  18 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  19 ---
  20  drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +++-
  21  1 file changed, 3 insertions(+), 1 deletion(-)
  22
  23 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  24 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  25 @@ -215,7 +215,9 @@ static int vc4_hdmi_connector_get_modes(
  26  static void vc4_hdmi_connector_reset(struct drm_connector *connector)
  27  {
  28         drm_atomic_helper_connector_reset(connector);
  29 -       drm_atomic_helper_connector_tv_reset(connector);
  30 +
  31 +       if (connector->state)
  32 +               drm_atomic_helper_connector_tv_reset(connector);
  33  }
  34
  35  static const struct drm_connector_funcs vc4_hdmi_connector_funcs = {