{"id":"CVE-2026-64307","title":"crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)\n\nSashiko notes:\n\n> if SEV initialization fails and KVM is actively running normal VMs, could a\n> userspace pro…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 1c3506ea8599a3ad1b9aae5cbd573134f8d18db7 < 345a6e869b33687e9268044bcaeeefd7c61da675","Linux >= ceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 441ea32cf2755a0dc593557056b00b7caa0651f5","Linux >= ceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 20f548cdac94860a164e5ebba4f7e4a01051cb06","Linux >= ceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 08f0e65e784c4b20e6e620dd4f68d8636073a3d2","Linux >= 6.12.75 < 6.12.97","Linux 6.16"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:34:35.438688Z"},"published":"2026-07-25","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:44:44.142Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64307","references":[{"url":"https://git.kernel.org/stable/c/345a6e869b33687e9268044bcaeeefd7c61da675"},{"url":"https://git.kernel.org/stable/c/441ea32cf2755a0dc593557056b00b7caa0651f5"},{"url":"https://git.kernel.org/stable/c/20f548cdac94860a164e5ebba4f7e4a01051cb06"},{"url":"https://git.kernel.org/stable/c/08f0e65e784c4b20e6e620dd4f68d8636073a3d2"}],"tags":["cve.org"],"epss":0.00169,"epssPercentile":0.06308,"ingestedAt":"2026-11-06T16:57:43.203Z","slug":"CVE-2026-64307","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)\n\nSashiko notes:\n\n> if SEV initialization fails and KVM is actively running normal VMs, could a\n> userspace process trigger this code path via /dev/sev ioctls (e.g.,\n> SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN\n> execution for an active VM trigger a general protection fault and crash the\n> host?\n\nRefuse to re-try initialization if SNP is not already initialized for\nSNP_CONFIG.\n\nThis is technically an ABI break: before if SNP initialization failed it\ncould be transparently retriggered by this ioctl, and if no VMs were\nrunning, everything worked fine. Hopefully this is enough of a corner case\nthat nobody will notice, but someone does, there are a few options:\n\n* do something like symbol_get() for kvm and refuse to initialize if KVM is\n  loaded\n* check each cpu's HSAVE_PA for non-zero data before re-initializing\n* once initialization has failed, continue to refuse to initialize until\n  the ccp module is unloaded\n\n## Affected\n\n- `Linux >= 1c3506ea8599a3ad1b9aae5cbd573134f8d18db7 < 345a6e869b33687e9268044bcaeeefd7c61da675`\n- `Linux >= ceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 441ea32cf2755a0dc593557056b00b7caa0651f5`\n- `Linux >= ceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 20f548cdac94860a164e5ebba4f7e4a01051cb06`\n- `Linux >= ceac7fb89e8da465aec3ac3c20477f912f5c3a6c < 08f0e65e784c4b20e6e620dd4f68d8636073a3d2`\n- `Linux >= 6.12.75 < 6.12.97`\n- `Linux 6.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}