{"id":"CVE-2026-72196","title":"fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass","summary":"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, …","severity":"high","cvss":8.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 9b3d8cc9d54fcded4de51b2b1026ae7182512077","Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 9b7c28d8c61bdb041936222a09a708531a1c2921","Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 0f13e823bf86bd1800168ea0bb5bca8b8500a81c","Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < d240cd98f5f7b65c90f6b2b6abe3232ccdc405ab","Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 49c86dae0c0ccb8d98ddcdc46987259389c816dd","Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 5e7b598660cfa8e5af172cf4c65cffc126333307","Linux 5.15"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:43:43.786684Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:45:01.462Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72196","references":[{"url":"https://git.kernel.org/stable/c/9b3d8cc9d54fcded4de51b2b1026ae7182512077"},{"url":"https://git.kernel.org/stable/c/9b7c28d8c61bdb041936222a09a708531a1c2921"},{"url":"https://git.kernel.org/stable/c/0f13e823bf86bd1800168ea0bb5bca8b8500a81c"},{"url":"https://git.kernel.org/stable/c/d240cd98f5f7b65c90f6b2b6abe3232ccdc405ab"},{"url":"https://git.kernel.org/stable/c/49c86dae0c0ccb8d98ddcdc46987259389c816dd"},{"url":"https://git.kernel.org/stable/c/5e7b598660cfa8e5af172cf4c65cffc126333307"}],"tags":["cve.org"],"epss":0.00185,"epssPercentile":0.07564,"ingestedAt":"2026-10-16T19:46:24.422Z","slug":"CVE-2026-72196","body":"## Overview\n\nIn 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]\n\n## Affected\n\n- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 9b3d8cc9d54fcded4de51b2b1026ae7182512077`\n- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 9b7c28d8c61bdb041936222a09a708531a1c2921`\n- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 0f13e823bf86bd1800168ea0bb5bca8b8500a81c`\n- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < d240cd98f5f7b65c90f6b2b6abe3232ccdc405ab`\n- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 49c86dae0c0ccb8d98ddcdc46987259389c816dd`\n- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 5e7b598660cfa8e5af172cf4c65cffc126333307`\n- `Linux 5.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":46.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}