CVE-2023-52898: NULL Pointer Dereference

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

xhci: Fix null pointer dereference when host dies

Make sure xhci_free_dev() and xhci_kill_endpoint_urbs() do not race and cause null pointer dereference when host suddenly dies.

Usb core may call xhci_free_dev() which frees the xhci->devs[slot_id] virt device at the same time that xhci_kill_endpoint_urbs() tries to loop through all the device's endpoints, checking if there are any cancelled urbs left to give back.

hold the xhci spinlock while freeing the virt device