|Description||PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via Reserved Memory Region Reporting, "RMRR"). These are typically used for platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory corruption.|
|Source||CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)|
Vulnerable and fixed packages
The table below lists information on source packages.
|xen (PTS)||stretch (security), stretch||4.8.5.final+shim4.10.4-1+deb9u12||fixed|
|buster, buster (security)||4.11.4+107-gef32c7afa2-1||fixed|
|bullseye (security), bullseye||4.14.3-1~deb11u1||vulnerable|
The information below is based on the following data on fixed versions.
|Package||Type||Release||Fixed Version||Urgency||Origin||Debian Bugs|
[bullseye] - xen <postponed> (Minor issue, fix along with next DSA)
[buster] - xen <not-affected> (Vulnerable code introduced later)
[stretch] - xen <not-affected> (Vulnerable code introduced later)