{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64533", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.795Z", "datePublished": "2026-07-27T06:32:33.740Z", "dateUpdated": "2026-08-17T04:57:11.184Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:57:11.184Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: validate lcns_follow in log_replay conversion\n\nlog_replay() converts DIR_PAGE_ENTRY_32 records into DIR_PAGE_ENTRY\nrecords when replaying version 0 restart tables.\n\nDuring this conversion, the memmove() length is derived directly from\nthe on-disk lcns_follow field:\n\n\tmemmove(&dp->vcn, &dp0->vcn_low,\n\t\t2 * sizeof(u64) +\n\t\t\t\tle32_to_cpu(dp->lcns_follow) * sizeof(u64));\n\ncheck_rstbl() validates restart table structure, but does not constrain\nper-entry lcns_follow values relative to the entry size. A malformed\nfilesystem image can provide an oversized lcns_follow value, causing\nthe conversion memmove() to access memory beyond the bounds of the\nallocated restart table buffer.\n\nThe same field is later used to bound iteration over page_lcns[],\nso validating lcns_follow during conversion also prevents downstream\nout-of-bounds access from the same malformed metadata.\n\nCompute the maximum valid lcns_follow from the already-validated\nrestart table entry size and reject entries that exceed this bound.\nReuse the existing t16/t32 scratch variables already declared in\nlog_replay() to avoid introducing new declarations.\n\n[almaz.alexandrovich@paragon-software.com: fixed the conflicts]" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The NTFS3 parser consumes malicious metadata from a locally mounted block device or filesystem image, not directly through a network protocol.\nAC:L - A structurally valid 44-byte entry with attacker-controlled lcns_follow=2 already crosses the heap-buffer boundary. No race or uncontrollable condition is required.\nPR:N - The attacker needs no account or capability to prepare and supply the crafted image; the init-namespace CAP_SYS_ADMIN mount requirement applies to the interacting victim or privileged mounting helper.\nUI:R - A victim or trusted mounting helper must cause the crafted NTFS filesystem to be mounted before journal replay processes the malicious metadata.\nS:U - The corruption compromises the kernel processing its own filesystem metadata and does not cross a distinct security authority such as a guest-to-host boundary.\nC:H - The attacker-controlled memmove performs a heap out-of-bounds read of attacker-selected extent, and the resulting memory corruption can be leveraged to disclose kernel memory.\nI:H - The same memmove writes beyond the allocated restart-table buffer, allowing corruption of adjacent slab objects and potentially arbitrary writes or control-flow hijacking.\nA:H - A sufficiently large lcns_follow reliably drives the kernel into an extensive invalid memory access, causing an oops or panic during mount and permitting repeated denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs3/fslog.c" ], "versions": [ { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "ca343a99806b4fc8e27c48f08be3445c5fcd1445", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "ddfc8683e1a627dbf1b83bacf8961443dd654258", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "57c071e2c4f30b9c6f5aacb6679aab1269fbae99", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "159f694d682e4215b3822ae31ed3a4631628fe55", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "7adb38279812c9c06b0e3fa7382f4d7887f3fa2d", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "32b9f8733feb241627fa5f564b1a99b5cae974c5", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "6a4c53a2e26a865565bd6a460961e8d6fcb32329", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs3/fslog.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "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": "5.15", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ca343a99806b4fc8e27c48f08be3445c5fcd1445" }, { "url": "https://git.kernel.org/stable/c/ddfc8683e1a627dbf1b83bacf8961443dd654258" }, { "url": "https://git.kernel.org/stable/c/57c071e2c4f30b9c6f5aacb6679aab1269fbae99" }, { "url": "https://git.kernel.org/stable/c/159f694d682e4215b3822ae31ed3a4631628fe55" }, { "url": "https://git.kernel.org/stable/c/7adb38279812c9c06b0e3fa7382f4d7887f3fa2d" }, { "url": "https://git.kernel.org/stable/c/32b9f8733feb241627fa5f564b1a99b5cae974c5" }, { "url": "https://git.kernel.org/stable/c/6a4c53a2e26a865565bd6a460961e8d6fcb32329" } ], "title": "fs/ntfs3: validate lcns_follow in log_replay conversion", "x_generator": { "engine": "bippy-1.2.0" } } } }