CVE-2023-53746

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

s390/vfio-ap: fix memory leak in vfio_ap device driver

The device release callback function invoked to release the matrix device uses the devgetdrvdata(device *dev) function to retrieve the pointer to the vfiomatrixdev object in order to free its storage. The problem is, this object is not stored as drvdata with the device; since the kfree function will accept a NULL pointer, the memory for the vfiomatrixdev object is never freed.

Since the device being released is contained within the vfiomatrixdev object, the container_of macro will be used to retrieve its pointer.