{"id":"CVE-2026-64307","state":"PUBLISHED","title":"crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)","description":"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 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","publishedAt":"2026-07-25T08:49:40.782Z","updatedAt":"2026-08-17T04:53:06.569Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1c3506ea8599a3ad1b9aae5cbd573134f8d18db7","status":"affected","lessThan":"345a6e869b33687e9268044bcaeeefd7c61da675","versionType":"git"},{"version":"ceac7fb89e8da465aec3ac3c20477f912f5c3a6c","status":"affected","lessThan":"441ea32cf2755a0dc593557056b00b7caa0651f5","versionType":"git"},{"version":"ceac7fb89e8da465aec3ac3c20477f912f5c3a6c","status":"affected","lessThan":"20f548cdac94860a164e5ebba4f7e4a01051cb06","versionType":"git"},{"version":"ceac7fb89e8da465aec3ac3c20477f912f5c3a6c","status":"affected","lessThan":"08f0e65e784c4b20e6e620dd4f68d8636073a3d2","versionType":"git"},{"version":"6.12.75","status":"affected","lessThan":"6.12.97","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]}],"references":["https://git.kernel.org/stable/c/345a6e869b33687e9268044bcaeeefd7c61da675","https://git.kernel.org/stable/c/441ea32cf2755a0dc593557056b00b7caa0651f5","https://git.kernel.org/stable/c/20f548cdac94860a164e5ebba4f7e4a01051cb06","https://git.kernel.org/stable/c/08f0e65e784c4b20e6e620dd4f68d8636073a3d2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64307.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64307","state":"PUBLISHED","datePublished":"2026-07-25T08:49:40.782Z","dateUpdated":"2026-08-17T04:53:06.569Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.779Z"},"containers":{"cna":{"title":"crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)","descriptions":[{"lang":"en","value":"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 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"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1c3506ea8599a3ad1b9aae5cbd573134f8d18db7","status":"affected","lessThan":"345a6e869b33687e9268044bcaeeefd7c61da675","versionType":"git"},{"version":"ceac7fb89e8da465aec3ac3c20477f912f5c3a6c","status":"affected","lessThan":"441ea32cf2755a0dc593557056b00b7caa0651f5","versionType":"git"},{"version":"ceac7fb89e8da465aec3ac3c20477f912f5c3a6c","status":"affected","lessThan":"20f548cdac94860a164e5ebba4f7e4a01051cb06","versionType":"git"},{"version":"ceac7fb89e8da465aec3ac3c20477f912f5c3a6c","status":"affected","lessThan":"08f0e65e784c4b20e6e620dd4f68d8636073a3d2","versionType":"git"},{"version":"6.12.75","status":"affected","lessThan":"6.12.97","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/crypto/ccp/sev-dev.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:53:06.569Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.75","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}