CVE-2022-48793: KVM: x86: nSVM: fix potential NULL derefernce on nested migration

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-16 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: nSVM: fix potential NULL derefernce on nested migration Turns out that due to review feedback and/or rebases I accidentally moved the call to nested_svm_load_cr3 to be too early, before the NPT is enabled, which is very wrong to do. KVM can't even access guest memory at that point as nested NPT is needed for that, and of course it won't initialize the walk_mmu, which is main issue the patch was addressing. Fix this for real.

Affected products

Linux kernel: from 5.13 before 5.15.25; from 5.16 before 5.16.11 — fixed in 5.15.25, 5.16.11

How to fix

Upgrade to a fixed version: Linux kernel 5.15.25, 5.16.11. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2022-48793 or the next vulnerability affects your stack