Bug 2011247 (CVE-2021-28702) - CVE-2021-28702 xen: administrators of guests which have been assigned RMRR-using PCI devices can cause DoS
Summary: CVE-2021-28702 xen: administrators of guests which have been assigned RMRR-us...
Alias: CVE-2021-28702
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 2011248
TreeView+ depends on / blocked
Reported: 2021-10-06 10:16 UTC by Marian Rehak
Modified: 2021-10-06 12:21 UTC (History)
2 users (show)

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Last Closed: 2021-10-06 12:21:24 UTC

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Description Marian Rehak 2021-10-06 10:16:03 UTC
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.

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Comment 1 Marian Rehak 2021-10-06 10:16:17 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 2011248]

Comment 2 Product Security DevOps Team 2021-10-06 12:21:24 UTC
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.

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