From: Maxime Ripard maxime@cerno.tech
stable inclusion from stable-v5.10.137 commit c015d12317c503dff7fc8f20a6ae00be255cb1a3 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit e55a07751146ef8ebc2c561564437b78f46405d3 ]
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.
Acked-by: Thomas Zimmermann tzimmermann@suse.de Reviewed-by: Dave Stevenson dave.stevenson@raspberrypi.com Suggested-by: Dave Stevenson dave.stevenson@raspberrypi.com Signed-off-by: Maxime Ripard maxime@cerno.tech Link: https://patchwork.freedesktop.org/patch/msgid/20201215154243.540115-5-maxime... Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- 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 9a90f22df3d2..978afe706ee2 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -209,7 +209,9 @@ 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_reset(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 = {