Xen up to 4.17.x Shadow Mode use after free

Summaryinfo

A vulnerability marked as problematic has been reported in Xen up to 4.17.x. This vulnerability affects unknown code of the component Shadow Mode Handler. Performing a manipulation results in use after free. This vulnerability is cataloged as CVE-2022-42332. The attack must be initiated from a local position. There is no exploit available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability classified as problematic has been found in Xen up to 4.17.x (Virtualization Software). This affects an unknown code of the component Shadow Mode Handler. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. The impact remains unknown. The summary by CVE is:

x86 shadow plus log-dirty mode use-after-free In environments where host assisted address translation is necessary but Hardware Assisted Paging (HAP) is unavailable, Xen will run guests in so called shadow mode. Shadow mode maintains a pool of memory used for both shadow page tables as well as auxiliary data structures. To migrate or snapshot guests, Xen additionally runs them in so called log-dirty mode. The data structures needed by the log-dirty tracking are part of aformentioned auxiliary data. In order to keep error handling efforts within reasonable bounds, for operations which may require memory allocations shadow mode logic ensures up front that enough memory is available for the worst case requirements. Unfortunately, while page table memory is properly accounted for on the code path requiring the potential establishing of new shadows, demands by the log-dirty infrastructure were not taken into consideration. As a result, just established shadow page tables could be freed again immediately, while other code is still accessing them on the assumption that they would remain allocated.

The weakness was shared 03/21/2023. It is possible to read the advisory at xenbits.xenproject.org. This vulnerability is uniquely identified as CVE-2022-42332 since 10/03/2022. The technical details are unknown and an exploit is not publicly available.

Applying a patch is able to eliminate this problem.

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Productinfo

Type

• Virtualization Software

Name

• Xen

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17

License

• open-source

CPE 2.3info

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CPE 2.2info

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