CVE-2023-46839

pci: phantom functions assigned to incorrect contexts

Description

PCI devices can make use of a functionality called phantom functions, that when enabled allows the device to generate requests using the IDs of functions that are otherwise unpopulated. This allows a device to extend the number of outstanding requests. Such phantom functions need an IOMMU context setup, but failure to setup the context is not fatal when the device is assigned. Not failing device assignment when such failure happens can lead to the primary device being assigned to a guest, while some of the phantom functions are assigned to a different domain.

Remediation

Workaround:

There is no mitigation (other than not passing through PCI devices with phantom functions to guests).

5.3

CVSS

Severity: Medium

CVSS 3.1 •

EPSS 0.05%

Affected: Xen Xen

References

Link	Tags
https://xenbits.xenproject.org/xsa/advisory-449.html

Frequently Asked Questions

What is the severity of CVE-2023-46839?: CVE-2023-46839 has been scored as a medium severity vulnerability.
How to fix CVE-2023-46839?: As a workaround for remediating CVE-2023-46839: There is no mitigation (other than not passing through PCI devices with phantom functions to guests).
Is CVE-2023-46839 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2023-46839 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-46839?: CVE-2023-46839 affects Xen Xen.

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