[SRU][N][PATCH 0/1] CVE-2024-50296

[Massimiliano Pellizzer]

https://ubuntu.com/security/CVE-2024-50296

[ Impact ]

net: hns3: fix kernel crash when uninstalling driver

When the driver is uninstalled and the VF is disabled concurrently, a
kernel crash occurs. The reason is that the two actions call function
pci_disable_sriov(). The num_VFs is checked to determine whether to
release the corresponding resources. During the second calling, num_VFs
is not 0 and the resource release function is called. However, the
corresponding resource has been released during the first invoking.

In this patch, when driver is removing, we get the device_lock()
to protect num_VFs, just like sriov_numvfs_store().

[ Fix ]

Oracular: Fixed via upstream stable updates (LP: #2091645)
Noble: Clean cherry pick from mainline
Jammy: Fixed via upstream stable updates (LP: #2089533)
Focal: Fixed via upstream stable updates (LP: #2089558)

[ Test Plan ]

Compiled and boot tested on arm64.
Loaded and unloded correctly the module hclge.

$ sudo modprobe hclge
$ lsmod | grep hclge
hclge                 176128  0
hnae3                  16384  1 hclge
$ sudo rmmod hclge
$ sudo rmmod hnae3

[ Where Problems Could Occur ]

The fix affects the hns3 driver in the networking subsystem.
A user might experience issues such as kernel panics during driver
uninstallation or when disabling virtual functions, leading to
system instability or crashes.