CVE-2025-38560

Summary

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

x86/sev: Evict cache lines during SNP memory validation

An SNP cache coherency vulnerability requires a cache line eviction mitigation when validating memory after a page state change to private. The specific mitigation is to touch the first and last byte of each 4K page that is being validated. There is no need to perform the mitigation when performing a page state change to shared and rescinding validation.

CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit that, when set, indicates that the software mitigation for this vulnerability is not needed.

Implement the mitigation and invoke it when validating memory (making it private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP guest is vulnerable.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 < 1fec416c03d0a64cc21aa04ce4aa14254b017e6aaffected
LinuxLinux4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 < 1fb873971e23c35c53823c62809a474a92bc3022affected
LinuxLinux4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 < aed15fc08f15dbb15822b2a0b653f67e76aa0fdfaffected
LinuxLinux4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 < a762a4c8d9e768b538b3cc60615361a8cf377de8affected
LinuxLinux4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 < f92af52e6dbd8d066d77beba451e0230482dc45baffected
LinuxLinux4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 < 7b306dfa326f70114312b320d083b21fa9481e1eaffected
LinuxLinux5.19affected
LinuxLinux0 < 5.19unaffected
LinuxLinux6.1.148 <= 6.1.*unaffected
LinuxLinux6.6.102 <= 6.6.*unaffected
LinuxLinux6.12.42 <= 6.12.*unaffected
LinuxLinux6.15.10 <= 6.15.*unaffected
LinuxLinux6.16.1 <= 6.16.*unaffected
LinuxLinux6.17 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

References