CVE-2022-49610: KVM: VMX: Prevent RSB underflow before vmenter

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: 2025-02-26 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Prevent RSB underflow before vmenter On VMX, there are some balanced returns between the time the guest's SPEC_CTRL value is written, and the vmenter. Balanced returns (matched by a preceding call) are usually ok, but it's at least theoretically possible an NMI with a deep call stack could empty the RSB before one of the returns. For maximum paranoia, don't allow *any* returns (balanced or otherwise) between the SPEC_CTRL write and the vmenter. [ bp: Fix 32-bit build. ]

Affected products

Linux kernel: before 5.18.14; 5.19-rc1, 5.19-rc2, 5.19-rc3, 5.19-rc4, 5.19-rc5, 5.19-rc6 — fixed in 5.18.14

How to fix

Upgrade to a fixed version: Linux kernel 5.18.14. Check the vendor advisory for mitigations.

References

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