Riskcovery

CVE-2026-72239

x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"

State
Published
Severity
9.3 Critical
Published
Aug 15, 2026
Updated
Aug 17, 2026
Reserved
Aug 9, 2026

Read the record on cve.org

Description

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

x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"

Revert

99cf1fb58e68 ("x86/virt/sev: Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN").

Section 8.8 of the SNP spec says:

Before invoking SNP_INIT_EX with INIT_RMP set to 1, software must ensure that no CPUs contain dirty cache lines for the memory containing the RMP.

Cachelines can be moved from cache to cache in a dirty state. The wbinvd_on_all_cpus() before SNP_INIT_EX flushes the caches for each CPU, but if the IPIs for WBINVD race with this dirty cacheline movement, it is possible that they may not get flushed, violating the firmware requirement.

Doing wbinvd_on_all_cpus() before setting SNPEn is safer since the RMP table is not yet in use.

[ Heroically bisected by Srikanth. ] [ bp: Massage commit message. ]

Scores

CVSSScoreVectorSource
3.19.3 CriticalCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 99cf1fb58e68291d408b4c4484181cf88f081857 to before e5158ff53fdff9c229bf13aa5f75eb17cdcfcd2dAffected
  • 99cf1fb58e68291d408b4c4484181cf88f081857 to before 4c2509f3b79756679a02bea649c6a7501b58f52cAffected
LinuxLinux
  • 7.1Affected
  • before 7.1Not affected
  • 7.1.5 through 7.1.*Not affected
  • 7.2 and laterNot affected

References

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