{"id":"CVE-2026-89782","summary":"fs/ntfs3: reject restart table growth beyond U16_MAX entries","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: reject restart table growth beyond U16_MAX entries\n\nDuring $LogFile replay, log_replay() indexes the transaction table by the\ntransact_id taken from the log record header.  check_log_rec() only\nverifies that transact_id is non-zero and properly aligned, not its\nmagnitude, so a crafted image can request an arbitrarily large index.\n\nalloc_rsttbl_from_idx() grows the table to cover that index via\nextend_rsttbl(), which passes the new entry count to init_rsttbl():\n\n\trt = init_rsttbl(esize, used + add);\n\nused + add is computed as u32 but init_rsttbl() takes a u16, and the\ncount is stored in struct RESTART_TABLE as a __le16.  When used + add\nexceeds U16_MAX it is truncated, init_rsttbl() allocates a table far\nsmaller than the index requires, and alloc_rsttbl_from_idx() then\ndereferences and writes at the original, untruncated offset -- an\nout-of-bounds access past the allocation, reachable by mounting a\ncrafted NTFS image.\n\n BUG: KASAN: use-after-free in alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950)\n Read of size 4 at addr ffff8880327ffff8 by task exploit\n  alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950)\n  log_replay (fs/ntfs3/fslog.c:4562)\n  ntfs_loadlog_and_replay (fs/ntfs3/fsntfs.c:324)\n  ntfs_fill_super (fs/ntfs3/super.c:1393)\n  get_tree_bdev_flags\n  vfs_get_tree\n  path_mount\n  __x64_sys_mount\n\nA restart table is limited to U16_MAX entries by its __le16 count, so a\nlarger growth request is invalid input.  Reject it in extend_rsttbl();\nall callers already handle a NULL return.","modified":"2026-09-17T03:47:26.600576669Z","published":"2026-09-16T08:48:21.093Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89782.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/111f8d74a19d85942ecbb3aba78f6f3c88e59391"},{"type":"WEB","url":"https://git.kernel.org/stable/c/339e59996ff193adcf1c438cf05f19e753beb3a7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/967a5ff8a614d10126b6d46db1ac040948d6cb42"},{"type":"WEB","url":"https://git.kernel.org/stable/c/aad605a450611e2a7b7cf9dd5724004d39192bfb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be218a01aadffe33ed4fc73e25276d676ebbd09d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ecde45cd81dc28f5696c312c5ce5a509962e9ab1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89782.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89782"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b46acd6a6a627d876898e1c84d3f84902264b445"},{"fixed":"caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56"},{"fixed":"339e59996ff193adcf1c438cf05f19e753beb3a7"},{"fixed":"ecde45cd81dc28f5696c312c5ce5a509962e9ab1"},{"fixed":"be218a01aadffe33ed4fc73e25276d676ebbd09d"},{"fixed":"aad605a450611e2a7b7cf9dd5724004d39192bfb"},{"fixed":"967a5ff8a614d10126b6d46db1ac040948d6cb42"},{"fixed":"111f8d74a19d85942ecbb3aba78f6f3c88e59391"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89782.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89782.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}