{"id":"CVE-2026-89782","state":"PUBLISHED","title":"fs/ntfs3: reject restart table growth beyond U16_MAX entries","description":"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.","publishedAt":"2026-09-16T08:48:21.093Z","updatedAt":"2026-10-19T08:52:34.456Z","severity":{"score":8.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"339e59996ff193adcf1c438cf05f19e753beb3a7","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"ecde45cd81dc28f5696c312c5ce5a509962e9ab1","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"be218a01aadffe33ed4fc73e25276d676ebbd09d","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"aad605a450611e2a7b7cf9dd5724004d39192bfb","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"967a5ff8a614d10126b6d46db1ac040948d6cb42","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"111f8d74a19d85942ecbb3aba78f6f3c88e59391","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/fslog.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/fslog.c"]}],"references":["https://git.kernel.org/stable/c/caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56","https://git.kernel.org/stable/c/339e59996ff193adcf1c438cf05f19e753beb3a7","https://git.kernel.org/stable/c/ecde45cd81dc28f5696c312c5ce5a509962e9ab1","https://git.kernel.org/stable/c/be218a01aadffe33ed4fc73e25276d676ebbd09d","https://git.kernel.org/stable/c/aad605a450611e2a7b7cf9dd5724004d39192bfb","https://git.kernel.org/stable/c/967a5ff8a614d10126b6d46db1ac040948d6cb42","https://git.kernel.org/stable/c/111f8d74a19d85942ecbb3aba78f6f3c88e59391"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89782.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89782","state":"PUBLISHED","datePublished":"2026-09-16T08:48:21.093Z","dateUpdated":"2026-10-19T08:52:34.456Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.765Z"},"containers":{"cna":{"title":"fs/ntfs3: reject restart table growth beyond U16_MAX entries","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"339e59996ff193adcf1c438cf05f19e753beb3a7","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"ecde45cd81dc28f5696c312c5ce5a509962e9ab1","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"be218a01aadffe33ed4fc73e25276d676ebbd09d","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"aad605a450611e2a7b7cf9dd5724004d39192bfb","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"967a5ff8a614d10126b6d46db1ac040948d6cb42","versionType":"git"},{"version":"b46acd6a6a627d876898e1c84d3f84902264b445","status":"affected","lessThan":"111f8d74a19d85942ecbb3aba78f6f3c88e59391","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/fslog.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/fslog.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56"},{"url":"https://git.kernel.org/stable/c/339e59996ff193adcf1c438cf05f19e753beb3a7"},{"url":"https://git.kernel.org/stable/c/ecde45cd81dc28f5696c312c5ce5a509962e9ab1"},{"url":"https://git.kernel.org/stable/c/be218a01aadffe33ed4fc73e25276d676ebbd09d"},{"url":"https://git.kernel.org/stable/c/aad605a450611e2a7b7cf9dd5724004d39192bfb"},{"url":"https://git.kernel.org/stable/c/967a5ff8a614d10126b6d46db1ac040948d6cb42"},{"url":"https://git.kernel.org/stable/c/111f8d74a19d85942ecbb3aba78f6f3c88e59391"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only while mounting a local NTFS block or loop device: path_mount → ntfs_fill_super → ntfs_loadlog_and_replay → log_replay → alloc_rsttbl_from_idx. ksmbd/nfsd never parse $LogFile; journal replay runs at fill_super, not while serving exported files.\nAC:L - The attacker fully controls on-disk $LogFile LFS_RECORD_HDR.transact_id. check_log_rec() only requires it non-zero and TRANSACTION_ENTRY-aligned, so a crafted index with used+add > U16_MAX truncates init_rsttbl() and hits the OOB access deterministically on mount with no race.\nPR:N - No account or privilege on the victim is required: a crafted NTFS volume on USB/removable media, a disk image, or shared storage is sufficient for udisks2/systemd automount or an administrator mount to run $LogFile replay as root.\nUI:N - Desktop, kiosk, automotive, and shared-workstation automounters mount attacker-supplied NTFS media and run log_replay() inside ntfs_fill_super() without the user opening files or confirming a dialog; attaching the crafted volume is sufficient to trigger the overflow.\nS:U - Heap out-of-bounds access and use-after-free occur in the host kernel during ntfs3 journal replay in the mounting process; impact stays within one kernel security authority and is not a VM escape or IOMMU/DMA bypass.\nC:H - After the truncated allocation, alloc_rsttbl_from_idx() reads a restart-table word at the original untruncated transact_id offset (KASAN use-after-free). That attacker-chosen heap index plus UAF of the freed old table enable arbitrary kernel memory disclosure.\nI:H - extend_rsttbl() memcpy's the old table into a truncated kmalloc buffer, then alloc_rsttbl_from_idx() memset's and writes RESTART_ENTRY_ALLOCATED at the untruncated offset, producing an OOB/UAF heap write that can corrupt adjacent slab objects for control-flow hijacking.\nA:H - KASAN reported use-after-free in alloc_rsttbl_from_idx() on mount of a crafted NTFS image; the out-of-bounds heap access during log replay can oops or panic the kernel and is repeatable on every mount of the malicious volume."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:52:34.456Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}