First published: Wed Oct 06 2021(Updated: )
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.
Credit: security@xen.org
Affected Software | Affected Version | How to fix |
---|---|---|
debian/xen | 4.11.4+107-gef32c7afa2-1 4.14.6-1 4.14.5+94-ge49571868d-1 4.17.1+2-gb773c48e36-1 4.17.2+55-g0b56bed864-1 | |
Xen Xen | >=4.13.0<=4.15.1 | |
Fedoraproject Fedora | =33 | |
Fedoraproject Fedora | =34 | |
Fedoraproject Fedora | =35 | |
Debian Debian Linux | =9.0 |
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