{"id":"CVE-2026-72199","summary":"ntfs: validate resident index root values on lookup","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: validate resident index root values on lookup\n\nResident $INDEX_ROOT values carry index header fields that callers\nconsume after lookup. Some callers already validate parts of the layout\nbefore walking entries, but those checks are scattered and do not cover\nall root header invariants, such as entries_offset alignment and lower\nbound, index_length, and allocated_size consistency.\n\nThe resident root resize paths now keep these header fields consistent\nwhile the value size changes: ntfs_ir_truncate() lowers\nindex.allocated_size before shrinking the resident value, and\nntfs_ir_reparent() grows the resident value before publishing a larger\nroot header. Lookup-time validation can therefore cover these invariants\nwithout tripping over the driver's own resize paths.\n\nAdd $INDEX_ROOT to the minimum resident value size table and validate the\nresident index header fields before returning the attribute from lookup.\nRequire 8-byte aligned index header fields, a sane entries_offset, an\nindex_length within allocated_size, allocated_size within the resident\nvalue, and enough entry space for at least an index entry header.\n\nThe shared validator already rejects non-resident records for\nresident-only attribute types, including $INDEX_ROOT.","modified":"2026-08-20T03:30:45.887833795Z","published":"2026-08-15T05:53:57.414Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72199.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/bfb01dd319b6b4c3e79756de7b75ccf0b9a0a247"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fcf5bf0e8570798970e3ae8c95d04765ba2c5b97"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72199.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72199"},{"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":"0a8ac0c1fa0b99a5b29002bc7f232ed7eafddef0"},{"fixed":"bfb01dd319b6b4c3e79756de7b75ccf0b9a0a247"},{"fixed":"fcf5bf0e8570798970e3ae8c95d04765ba2c5b97"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72199.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72199.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}