crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT)
In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? The SNP_COMMIT command does not require the firmware to be in any particular state. Skip initializing it if it was previously uninitialized. The SEV-SNP firmware specification doc 56860 does not mention SNP_COMMIT in Table 5 as a command that is allowed in the UNINIT state, but it is in fact allowed and a future documentation update will reflect that.
02 / AFFECTED SOFTWARE
Affected packages
21 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT) Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? The SNP_COMMIT command does not require the firmware to be in any particular state. Skip initializing it if it was previously uninitialized. The SEV-SNP firmware specification doc 56860 does not mention SNP_COMMIT in Table 5 as a command that is allowed in the UNINIT state, but it is in fact allowed and a future documentation update will reflect that.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/5a1364da2f04217a36e2fdfa2db4ee025b383a20
- https://git.kernel.org/stable/c/67ed191b4c8bdf432a3f32d1eb302880b4795cd1
- https://git.kernel.org/stable/c/74768f73854d647a6462f252dc8782ab8a835211
- https://git.kernel.org/stable/c/7a361c74bb12f3398c388905f1d325be642cd36e
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64309.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-64309