In the Linux kernel, the following vulnerability has been resolved: thermal/drivers/rcar: Fix error checking in probe() This code accidentally calls thermal_zone_device_enable() before checking whether thermal_zone_device_register_with…

Overview

In the Linux kernel, the following vulnerability has been resolved:

thermal/drivers/rcar: Fix error checking in probe()

This code accidentally calls thermal_zone_device_enable() before checking whether thermal_zone_device_register_with_trips() failed. Move the call until later to avoid an error pointer dereference of "priv->zone".

The driver works differently depending on if we are using OF thermal or not. We use thermal_add_hwmon_sysfs() if we are using OF thermal and call thermal_zone_device_enable() if not. We can share same error check for if either of these fail.

Moving the thermal_zone_device_enable() call is a bit cleaner as well. The original code used a three step process to cleanup:

1. Call thermal_zone_device_unregister() to cleanup.
2. Set priv->zone to an error pointer to preserve the error code.
3. Set priv->zone to NULL to avoid a second call to thermal_zone_device_unregister() in the rcar_thermal_remove() function.

Now we can just do a direct goto error_unregister and rcar_thermal_remove() handles the cleanup properly.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.