> -----Original Message----- > From: Colin King <[email protected]> > Sent: Wednesday, February 24, 2021 12:49 AM > To: Jani Nikula <[email protected]>; Joonas Lahtinen > <[email protected]>; Vivi, Rodrigo <[email protected]>; > David Airlie <[email protected]>; Daniel Vetter <[email protected]>; C, > Ramalingam > <[email protected]>; Gupta, Anshuman <[email protected]>; > [email protected]; [email protected] > Cc: [email protected]; [email protected] > Subject: [PATCH][next] drm/i915/hdcp: Fix null pointer dereference of > connector->encoder > > From: Colin Ian King <[email protected]> > > The recent commit 6c63e6e14da7 ("drm/i915/hdcp: No HDCP when encoder is't > initialized") added a null pointer check on connector->encoder hence implying > that it could potentially be null. This means that the initialization of > dig_port via > the call intel_attached_dig_port may cause a null pointer dereference on > connector->encoder. Fix this by only assigning dig_port after a null check has > been performed on connector->encoder. > > Addresses-Coverity: ("Dereference before null check") > Fixes: 36e5e7042b20 ("drm/i915: Don't fully disable HDCP on a port if multiple > pipes are using it") > Signed-off-by: Colin Ian King <[email protected]> Looks good to me. Reviewed-by: Anshuman Gupta <[email protected]> > --- > drivers/gpu/drm/i915/display/intel_hdcp.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c > b/drivers/gpu/drm/i915/display/intel_hdcp.c > index ae1371c36a32..7525ea31766c 100644 > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c > @@ -2260,7 +2260,7 @@ int intel_hdcp_enable(struct intel_connector > *connector, > const struct intel_crtc_state *pipe_config, u8 > content_type) > { > struct drm_i915_private *dev_priv = to_i915(connector->base.dev); > - struct intel_digital_port *dig_port = > intel_attached_dig_port(connector); > + struct intel_digital_port *dig_port; > struct intel_hdcp *hdcp = &connector->hdcp; > unsigned long check_link_interval = DRM_HDCP_CHECK_PERIOD_MS; > int ret = -EINVAL; > @@ -2274,6 +2274,7 @@ int intel_hdcp_enable(struct intel_connector > *connector, > return -ENODEV; > } > > + dig_port = intel_attached_dig_port(connector); > mutex_lock(&hdcp->mutex); > mutex_lock(&dig_port->hdcp_mutex); > drm_WARN_ON(&dev_priv->drm, > -- > 2.30.0
