From: Colin Ian King colin.king@canonical.com
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 colin.king@canonical.com --- 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,
-----Original Message----- From: Colin King colin.king@canonical.com Sent: Wednesday, February 24, 2021 12:49 AM To: Jani Nikula jani.nikula@linux.intel.com; Joonas Lahtinen joonas.lahtinen@linux.intel.com; Vivi, Rodrigo rodrigo.vivi@intel.com; David Airlie airlied@linux.ie; Daniel Vetter daniel@ffwll.ch; C, Ramalingam ramalingam.c@intel.com; Gupta, Anshuman anshuman.gupta@intel.com; intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org Cc: kernel-janitors@vger.kernel.org; linux-kernel@vger.kernel.org Subject: [PATCH][next] drm/i915/hdcp: Fix null pointer dereference of connector->encoder
From: Colin Ian King colin.king@canonical.com
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 colin.king@canonical.com
Looks good to me. Reviewed-by: Anshuman Gupta anshuman.gupta@intel.com
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
dri-devel@lists.freedesktop.org
-
Colin King -
Gupta, Anshuman