CVE-2023-53596

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

drivers: base: Free devm resources when unregistering a device

In the current code, devres_release_all() 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 devres_release_all() 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 device_del()) that got reverted by commit a525a3ddeaca (driver core: free devres in device_release) over memory leaks concerns.

This patch effectively combines the two commits mentioned above to release the resources both on device_del() and device_release() and get the best of both worlds.

Affected Software

References

• https://git.kernel.org/stable/c/297992e5c63528e603666e36081836204fc36ec9
• https://git.kernel.org/stable/c/3bcc4c2a096e8342c8c719e595ce15de212694dd
• https://git.kernel.org/stable/c/699fb50d99039a50e7494de644f96c889279aca3
• https://git.kernel.org/stable/c/c8c426fae26086a0ca8ab6cc6da2de79810ec038