CVE-2025-21802

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

net: hns3: fix oops when unload drivers paralleling

When unload hclge driver, it tries to disable sriov first for each
ae_dev node from hnae3_ae_dev_list. If user unloads hns3 driver at
the time, because it removes all the ae_dev nodes, and it may cause
oops.

But we can't simply use hnae3_common_lock for this. Because in the
process flow of pci_disable_sriov(), it will trigger the remove flow
of VF, which will also take hnae3_common_lock.

To fixes it, introduce a new mutex to protect the unload process.