Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 to < 1fec416c03d0a64cc21aa04ce4aa14254b017e6aaffected4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 to < 1fb873971e23c35c53823c62809a474a92bc3022affected4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 to < aed15fc08f15dbb15822b2a0b653f67e76aa0fdfaffected4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 to < a762a4c8d9e768b538b3cc60615361a8cf377de8affected4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 to < f92af52e6dbd8d066d77beba451e0230482dc45baffected4f9c403e44e5e88feb27d5e617d1adc9cc7ef684 to < 7b306dfa326f70114312b320d083b21fa9481e1eaffected
Linux Linux
Default version status: affected
5.19affected0 to < 5.19unaffected6.1.148 to ≤ 6.1.*unaffected6.6.102 to ≤ 6.6.*unaffected6.12.42 to ≤ 6.12.*unaffected6.15.10 to ≤ 6.15.*unaffected6.16.1 to ≤ 6.16.*unaffected6.17 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/1fec416c03d0a64cc21aa04ce4aa14254b017e6a ↗
- https://git.kernel.org/stable/c/1fb873971e23c35c53823c62809a474a92bc3022 ↗
- https://git.kernel.org/stable/c/aed15fc08f15dbb15822b2a0b653f67e76aa0fdf ↗
- https://git.kernel.org/stable/c/a762a4c8d9e768b538b3cc60615361a8cf377de8 ↗
- https://git.kernel.org/stable/c/f92af52e6dbd8d066d77beba451e0230482dc45b ↗
- https://git.kernel.org/stable/c/7b306dfa326f70114312b320d083b21fa9481e1e ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html ↗