CVE-2023-53123

/// Technical description

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

PCI: s390: Fix use-after-free of PCI resources with per-function hotplug

On s390 PCI functions may be hotplugged individually even when they

belong to a multi-function device. In particular on an SR-IOV device VFs

may be removed and later re-added.

In commit a50297cf8235 ("s390/pci: separate zbus creation from

scanning") it was missed however that struct pci_bus and struct

zpci_bus's resource list retained a reference to the PCI functions MMIO

resources even though those resources are released and freed on

hot-unplug. These stale resources may subsequently be claimed when the

PCI function re-appears resulting in use-after-free.

One idea of fixing this use-after-free in s390 specific code that was

investigated was to simply keep resources around from the moment a PCI

function first appeared until the whole virtual PCI bus created for

a multi-function device disappears. The problem with this however is

that due to th

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References