In the Linux kernel, the following vulnerability has been resolved:
drivers: base: Free devm resources when unregistering a device
In the current code, devresreleaseall() only gets called if the device has a bus and has been probed.
This leads to issues when using bus-less or driver-less devices where the device might never get freed if a managed resource holds a reference to the device. This is happening in the DRM framework for example.
We should thus call devresreleaseall() in the device_del() function to make sure that the device-managed actions are properly executed when the device is unregistered, even if it has neither a bus nor a driver.
This is effectively the same change than commit 2f8d16a996da ("devres: release resources on devicedel()") that got reverted by commit a525a3ddeaca ("driver core: free devres in devicerelease") over memory leaks concerns.
This patch effectively combines the two commits mentioned above to release the resources both on devicedel() and devicerelease() and get the best of both worlds.