CVE-2025-38735

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

gve: prevent ethtool ops after shutdown

A crash can occur if an ethtool operation is invoked

after shutdown() is called.

shutdown() is invoked during system shutdown to stop DMA operations

without performing expensive deallocations. It is discouraged to

unregister the netdev in this path, so the device may still be visible

to userspace and kernel helpers.

In gve, shutdown() tears down most internal data structures. If an

ethtool operation is dispatched after shutdown(), it will dereference

freed or NULL pointers, leading to a kernel panic. While graceful

shutdown normally quiesces userspace before invoking the reboot

syscall, forced shutdowns (as observed on GCP VMs) can still trigger

this path.

Fix by calling netif_device_detach() in shutdown().

This marks the device as detached so the ethtool ioctl handler

will skip dispatching operations to the driver.