{"id":"CVE-2026-72196","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-72196","generatedAt":"2026-10-28T04:16:48.939Z","title":"In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass In log_replay()'s analysis pass, after find_dp() returns a valid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple,…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass\n\nIn log_replay()'s analysis pass, after find_dp() returns a\nvalid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple,\nthe copy_lcns block walks lrh->lcns_follow further entries:\n\n\tt16 = le16_to_cpu(lrh->lcns_follow);\n\tfor (i = 0; i < t16; i++) {\n\t    size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -\n\t                        le64_to_cpu(dp->vcn));\n\t    dp->page_lcns[j + i] = lrh->page_lcns[i];\n\t}\n\nfind_dp() only validates that target_vcn falls within\n[dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST\ncluster is covered.  The walk through the further entries is\nnot bounded against dp->lcns_follow.  For a malformed LRH\nwhere target_vcn = dp->vcn + dp->lcns_follow - 1 and\nlrh->lcns_follow > 1, the i > 0 writes overflow the dp's\nallocated page_lcns[] array.\n\nAdd the missing j + lrh->lcns_follow <= dp->lcns_follow guard.\n\nReproduced under UML+KASAN on mainline 8d90b09e6741 as a\nslab-out-of-bounds write of size 8 from log_replay+0x68d4 on\nthe mount path.\n\nThis is distinct from Pavitra Jha's 2026-05-02 patch\n(\"fs/ntfs3: validate lcns_follow in log_replay conversion\",\n<20260502154252.164586-1-jhapavitra98@gmail.com>) which\naddresses the separate version-0 dirty-page-table conversion\npath's memmove(&dp->vcn, ...) call.  The two fixes are\ncomplementary; both should land.\n\n[almaz.alexandrovich@paragon-software.com: clang-formatted the changes,\nfixed conflicts]","published":"2026-08-15T06:21:38.000Z","lastModified":"2026-10-16T19:17:14.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":[],"epss":{"score":0.00185,"percentile":0.08013,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0f13e823bf86bd1800168ea0bb5bca8b8500a81c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/49c86dae0c0ccb8d98ddcdc46987259389c816dd","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5e7b598660cfa8e5af172cf4c65cffc126333307","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9b3d8cc9d54fcded4de51b2b1026ae7182512077","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9b7c28d8c61bdb041936222a09a708531a1c2921","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d240cd98f5f7b65c90f6b2b6abe3232ccdc405ab","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72196","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}