CVE-2024-50115

Source
https://nvd.nist.gov/vuln/detail/CVE-2024-50115
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-50115.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2024-50115
Downstream
Related
Published
2024-11-05T18:15:14Z
Modified
2025-08-09T20:01:26Z
Severity
  • 7.1 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

KVM: nSVM: Ignore nCR3[4:0] when loading PDPTEs from memory

Ignore nCR3[4:0] when loading PDPTEs from memory for nested SVM, as bits 4:0 of CR3 are ignored when PAE paging is used, and thus VMRUN doesn't enforce 32-byte alignment of nCR3.

In the absolute worst case scenario, failure to ignore bits 4:0 can result in an out-of-bounds read, e.g. if the target page is at the end of a memslot, and the VMM isn't using guard pages.

Per the APM:

The CR3 register points to the base address of the page-directory-pointer table. The page-directory-pointer table is aligned on a 32-byte boundary, with the low 5 address bits 4:0 assumed to be 0.

And the SDM's much more explicit:

4:0 Ignored

Note, KVM gets this right when loading PDPTRs, it's only the nSVM flow that is broken.

References

Affected packages