CVE-2026-64307

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)<br /> <br /> Sashiko notes:<br /> <br /> &gt; if SEV initialization fails and KVM is actively running normal VMs, could a<br /> &gt; userspace process trigger this code path via /dev/sev ioctls (e.g.,<br /> &gt; SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN<br /> &gt; execution for an active VM trigger a general protection fault and crash the<br /> &gt; host?<br /> <br /> Refuse to re-try initialization if SNP is not already initialized for<br /> SNP_CONFIG.<br /> <br /> This is technically an ABI break: before if SNP initialization failed it<br /> could be transparently retriggered by this ioctl, and if no VMs were<br /> running, everything worked fine. Hopefully this is enough of a corner case<br /> that nobody will notice, but someone does, there are a few options:<br /> <br /> * do something like symbol_get() for kvm and refuse to initialize if KVM is<br /> loaded<br /> * check each cpu&amp;#39;s HSAVE_PA for non-zero data before re-initializing<br /> * once initialization has failed, continue to refuse to initialize until<br /> the ccp module is unloaded