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. ]
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. ]
Published:
2026-08-15
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
No advisories yet.
References
History
Sat, 15 Aug 2026 06:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. ] | |
| Title | x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN" | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:54:28.166Z
Reserved: 2026-08-09T03:40:39.914Z
Link: CVE-2026-72239
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-15T06:21:50.970
Modified: 2026-08-15T06:21:50.970
Link: CVE-2026-72239
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.