CVE-2023-46842

Description

Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and other modes. This in particular means that they may set registers used to pass 32-bit-mode hypercall arguments to values outside of the range 32-bit code would be able to set them to. When processing of hypercalls takes a considerable amount of time, the hypervisor may choose to invoke a hypercall continuation. Doing so involves putting (perhaps updated) hypercall arguments in respective registers. For guests not running in 64-bit mode this further involves a certain amount of translation of the values. Unfortunately internal sanity checking of these translated values assumes high halves of registers to always be clear when invoking a hypercall. When this is found not to be the case, it triggers a consistency check in the hypervisor and causes a crash.

Reserved 2023-10-27 | Published 2024-05-16 | Updated 2025-04-30 | Assigner XEN

Product status

Default status
unknown

consult Xen advisory XSA-454
unknown

Credits

This issue was discovered by Manuel Andreas of Technical University of Munich. finder

References

xenbits.xenproject.org/xsa/advisory-454.html

cve.org (CVE-2023-46842)

nvd.nist.gov (CVE-2023-46842)

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