From: Won Chung Date: Mon, 18 Apr 2022 17:59:31 +0000 (+0000) Subject: misc/mei: Add NULL check to component match callback functions X-Git-Tag: v6.6.17~7346^2~10^2~8 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=84d4333c1e28cedfad37c5347b4a94a3565a454f;p=platform%2Fkernel%2Flinux-rpi.git misc/mei: Add NULL check to component match callback functions Currently, component_match callback functions used in mei refers to the driver name, assuming that the component device being matched has a driver bound. It can cause a NULL pointer dereference when a device without a driver bound registers a component. This is due to the nature of the component framework where all registered components are matched in any component_match callback functions. So even if a component is registered by a totally irrelevant device, that component is also shared to these callbacks for i915 driver. To prevent totally irrelevant device being matched for i915 and causing a NULL pointer dereference for checking driver name, add a NULL check on dev->driver to check if there is a driver bound before checking the driver name. In the future, the string compare on the driver name, "i915" may need to be refactored too. Reviewed-by: Heikki Krogerus Reviewed-by: Prashant Malani Signed-off-by: Won Chung Acked-by: Tomas Winkler Signed-off-by: Mika Westerberg --- diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c index ec2a4fc..e889a8b 100644 --- a/drivers/misc/mei/hdcp/mei_hdcp.c +++ b/drivers/misc/mei/hdcp/mei_hdcp.c @@ -784,7 +784,7 @@ static int mei_hdcp_component_match(struct device *dev, int subcomponent, { struct device *base = data; - if (strcmp(dev->driver->name, "i915") || + if (!dev->driver || strcmp(dev->driver->name, "i915") || subcomponent != I915_COMPONENT_HDCP) return 0; diff --git a/drivers/misc/mei/pxp/mei_pxp.c b/drivers/misc/mei/pxp/mei_pxp.c index f7380d3..5c39457 100644 --- a/drivers/misc/mei/pxp/mei_pxp.c +++ b/drivers/misc/mei/pxp/mei_pxp.c @@ -131,7 +131,7 @@ static int mei_pxp_component_match(struct device *dev, int subcomponent, { struct device *base = data; - if (strcmp(dev->driver->name, "i915") || + if (!dev->driver || strcmp(dev->driver->name, "i915") || subcomponent != I915_COMPONENT_PXP) return 0;