# CVE-2023-46839: xen: PCI devices can make use of a functionality called phantom functions, that when enabled allows the device to generate...

CVE-2023-46839 is fixed in xen on 1 platform, first by DEBIAN-CVE-2023-46839, released March 20, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-46839
- Priority: Routine
- CVSS: 5.3 (medium)
- EPSS: 0.0081
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 20, 2024

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | xen Debian 12.15 (bookworm) | 4.17.3+10-g091466ba55-1~deb12u1 | [DEBIAN-CVE-2023-46839](https://patchblox.com/security/data/fix/linux/debian-cve-2023-46839.md) | Mar 20, 2024 |
| Linux | xen Debian 13.5 (trixie) | 4.17.3+10-g091466ba55-1 | [DEBIAN-CVE-2023-46839](https://patchblox.com/security/data/fix/linux/debian-cve-2023-46839.md) | Mar 20, 2024 |
| Linux | xen Debian 14 | 4.17.3+10-g091466ba55-1 | [DEBIAN-CVE-2023-46839](https://patchblox.com/security/data/fix/linux/debian-cve-2023-46839.md) | Mar 20, 2024 |

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