{"id":"CVE-2026-64533","summary":"fs/ntfs3: validate lcns_follow in log_replay conversion","details":"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-\u003evcn, &dp0-\u003evcn_low,\n\t\t2 * sizeof(u64) +\n\t\t\t\tle32_to_cpu(dp-\u003elcns_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]","modified":"2026-07-31T03:59:07.312844440Z","published":"2026-07-27T06:32:33.740Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64533.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/159f694d682e4215b3822ae31ed3a4631628fe55"},{"type":"WEB","url":"https://git.kernel.org/stable/c/32b9f8733feb241627fa5f564b1a99b5cae974c5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/57c071e2c4f30b9c6f5aacb6679aab1269fbae99"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6a4c53a2e26a865565bd6a460961e8d6fcb32329"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7adb38279812c9c06b0e3fa7382f4d7887f3fa2d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ca343a99806b4fc8e27c48f08be3445c5fcd1445"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ddfc8683e1a627dbf1b83bacf8961443dd654258"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64533.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64533"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b46acd6a6a627d876898e1c84d3f84902264b445"},{"fixed":"ca343a99806b4fc8e27c48f08be3445c5fcd1445"},{"fixed":"ddfc8683e1a627dbf1b83bacf8961443dd654258"},{"fixed":"57c071e2c4f30b9c6f5aacb6679aab1269fbae99"},{"fixed":"159f694d682e4215b3822ae31ed3a4631628fe55"},{"fixed":"7adb38279812c9c06b0e3fa7382f4d7887f3fa2d"},{"fixed":"32b9f8733feb241627fa5f564b1a99b5cae974c5"},{"fixed":"6a4c53a2e26a865565bd6a460961e8d6fcb32329"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64533.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64533.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}]}