CVE-2026-64309

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.