{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74404", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.892Z", "datePublished": "2026-08-15T05:59:14.073Z", "dateUpdated": "2026-10-16T19:05:43.034Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:46:46.485Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one\n\nSashiko notes:\n\n> regarding the bounds check in snp_filter_reserved_mem_regions()\n> called via walk_iomem_res_desc(): does the check\n> if ((range_list->num_elements * 16 + 8) > PAGE_SIZE)\n> allow an off-by-one heap buffer overflow?\n>\n> If range_list->num_elements is 255, 255 * 16 + 8 = 4088, which is <= 4096.\n> Writing range->base (8 bytes) fills 4088-4095, but writing range->page_count\n> (4 bytes) would write to 4096-4099, overflowing the kzalloc-allocated\n> PAGE_SIZE buffer.\n\nFix this by accounting for the entry about to be written to, in addition to\nthe entries that are already allocated." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflow is reached only via local host paths—KVM VM ioctl KVM_SEV_INIT2 (sev_guest_init2→sev_platform_init→__sev_snp_init_locked) or kernel boot-time SEV-SNP platform init—not through any network, Bluetooth, or physical bus handler.\nAC:L - Once on an AMD SEV-SNP host with SNP firmware ≥1.52, a caller can deterministically trigger SNP_INIT_EX initialization via KVM_SEV_INIT2; no race or attacker-uncontrollable timing is required, only a firmware memory map with ≥256 matching reserved/ACPI/PMEM iomem regions.\nPR:L - Exploitation requires local hypervisor access to create an SNP-capable KVM VM and issue KVM_SEV_INIT2 (typical /dev/kvm or kvm-group hypervisor operator), not unauthenticated remote access; comparable KVM ioctl CVEs in this repo score this as low privilege rather than init-namespace root only.\nUI:N - No victim interaction is needed beyond the attacker (or boot sequence) invoking SNP platform initialization; the bug fires automatically while enumerating the system iomem map during SNP_INIT_EX setup.\nS:U - The corruption occurs in host kernel heap memory during hypervisor SEV-SNP platform initialization by a host-side caller; it is not a guest-to-host VM escape, IOMMU/DMA bypass, or cross-authority sandbox breakout.\nC:H - The off-by-one permits a 4-byte out-of-bounds write of page_count past a PAGE_SIZE kzalloc buffer, corrupting adjacent kmalloc slab memory in ways that can be leveraged for kernel information disclosure.\nI:H - A controlled heap buffer overflow (even 4 bytes) can corrupt adjacent kernel objects and be developed into arbitrary kernel memory writes or control-flow hijacking, satisfying high integrity impact per kernel OOB-write guidance.\nA:H - Heap metadata/object corruption during SNP_INIT_EX can cause kernel oops/panic or leave the host in a failed state, especially on confidential-computing servers where SNP initialization is on the critical boot/VM-launch path." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/crypto/ccp/sev-dev.c" ], "versions": [ { "version": "1ca5614b84eed5904f65f143e0e7aaab0ac4c6b2", "lessThan": "830c1f3e71989448652973375ef5e39b6ede47a3", "status": "affected", "versionType": "git" }, { "version": "1ca5614b84eed5904f65f143e0e7aaab0ac4c6b2", "lessThan": "c5c79d92da0f9a09f48be5e2aabed2d6d1a96294", "status": "affected", "versionType": "git" }, { "version": "1ca5614b84eed5904f65f143e0e7aaab0ac4c6b2", "lessThan": "af7341616b742ad2c374a90998bd650a035f694d", "status": "affected", "versionType": "git" }, { "version": "1ca5614b84eed5904f65f143e0e7aaab0ac4c6b2", "lessThan": "1b864b6cb213bbd7b406e9b2e98c962077f300df", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/crypto/ccp/sev-dev.c" ], "versions": [ { "version": "6.9", "status": "affected" }, { "version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/830c1f3e71989448652973375ef5e39b6ede47a3" }, { "url": "https://git.kernel.org/stable/c/c5c79d92da0f9a09f48be5e2aabed2d6d1a96294" }, { "url": "https://git.kernel.org/stable/c/af7341616b742ad2c374a90998bd650a035f694d" }, { "url": "https://git.kernel.org/stable/c/1b864b6cb213bbd7b406e9b2e98c962077f300df" } ], "title": "crypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74404", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T18:55:44.374861Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:43.034Z" } } ] } }