CVE-2023-46839: pci: phantom functions assigned to incorrect contexts
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.
Affected Software
Remediation
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2023-46839?
CVE-2023-46839 has a medium severity rating, indicating potential risks in environments using affected PCI devices.
How do I fix CVE-2023-46839?
To mitigate CVE-2023-46839, it's recommended to disable the use of phantom functions on the affected devices.
Which software is affected by CVE-2023-46839?
CVE-2023-46839 specifically affects the Xen Hypervisor when used with certain PCI devices.
What are phantom functions in relation to CVE-2023-46839?
Phantom functions allow PCI devices to generate requests using IDs of non-populated functions, potentially extending the number of outstanding requests.
Are there any known workarounds for CVE-2023-46839?
Currently, the main workaround for CVE-2023-46839 is to disable the phantom functions feature in affected devices.