{"id":"CVE-2026-72192","state":"PUBLISHED","title":"ntfs3: bound to_move in indx_insert_into_root before hdr_insert_head","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: bound to_move in indx_insert_into_root before hdr_insert_head\n\nindx_insert_into_root() promotes a full resident $INDEX_ROOT into\n$INDEX_ALLOCATION and copies all non-last resident root entries into\na newly allocated INDEX_BUFFER via hdr_insert_head(). The source\nbyte count 'to_move' is summed from the on-disk resident entry sizes\nand is independent of the destination buffer size, which comes from\nroot->index_block_size (via indx->index_bits).\n\nA crafted NTFS image that keeps a valid, full resident root but\nshrinks root->index_block_size down to 512 after the root has been\npopulated makes hdr_insert_head() memcpy attacker-controlled resident\nentry bytes past the end of the kmalloc(1u << indx->index_bits)\nallocation returned by indx_new(). For a 512-byte destination and a\nresident root whose non-last entries total 560 bytes, the memcpy\noverruns by 120 bytes and a following memmove extends the highest\nwritten offset to 136 bytes past the allocation. The overflow bytes\nare a direct copy of on-disk entries (via kmemdup), so they are\nfully attacker-controlled.\n\nThe write is reachable from unprivileged open(O_CREAT) on a mounted\ncrafted NTFS image: a single sufficiently long create in a directory\nwhose resident root is already full forces root promotion and\ntriggers the copy.\n\nThis is a controlled out-of-bounds write of 120-136 bytes past a\nkmalloc(index_block_size) allocation, with attacker-controlled\ncontent. It is a bounded adjacent-heap corruption primitive; it is\nnot an arbitrary-address write. Successful exploitation into a named\nvictim object depends on the surrounding slab layout.\n\nReject the copy at the sink. The destination's INDEX_HDR already\nreports hdr_total (the payload capacity of the new buffer) and\nhdr_used (the bytes already consumed by the terminal END entry\ninstalled by indx_new()); require that to_move fits in the remaining\npayload before calling hdr_insert_head(). On mismatch, fail with\n-EINVAL and mark the filesystem as having a detected on-disk\ninconsistency, which is the same behaviour as the surrounding\nvalidation in this function.","publishedAt":"2026-08-15T05:53:52.634Z","updatedAt":"2026-10-16T18:45:00.935Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/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":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"0af83b8155cc848e9f5d2c36e20a70d024214649","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"cb3161deebcaf8d36d3115abf452c633f2180fc1","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"53c5f3b2da3774b41534728aba295c098c9efa19","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"194b00c99ba971fa7cf6acd747a36032c6de54eb","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"aaa1f956c0fc41089a4a534da7df91552a08a47c","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"d240f5f9d036b8180224954d9873f172b6be4dd8","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/index.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/index.c"]}],"references":["https://git.kernel.org/stable/c/0af83b8155cc848e9f5d2c36e20a70d024214649","https://git.kernel.org/stable/c/cb3161deebcaf8d36d3115abf452c633f2180fc1","https://git.kernel.org/stable/c/53c5f3b2da3774b41534728aba295c098c9efa19","https://git.kernel.org/stable/c/194b00c99ba971fa7cf6acd747a36032c6de54eb","https://git.kernel.org/stable/c/aaa1f956c0fc41089a4a534da7df91552a08a47c","https://git.kernel.org/stable/c/d240f5f9d036b8180224954d9873f172b6be4dd8","https://git.kernel.org/stable/c/9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72192.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72192","state":"PUBLISHED","datePublished":"2026-08-15T05:53:52.634Z","dateUpdated":"2026-10-16T18:45:00.935Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.911Z"},"containers":{"cna":{"title":"ntfs3: bound to_move in indx_insert_into_root before hdr_insert_head","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: bound to_move in indx_insert_into_root before hdr_insert_head\n\nindx_insert_into_root() promotes a full resident $INDEX_ROOT into\n$INDEX_ALLOCATION and copies all non-last resident root entries into\na newly allocated INDEX_BUFFER via hdr_insert_head(). The source\nbyte count 'to_move' is summed from the on-disk resident entry sizes\nand is independent of the destination buffer size, which comes from\nroot->index_block_size (via indx->index_bits).\n\nA crafted NTFS image that keeps a valid, full resident root but\nshrinks root->index_block_size down to 512 after the root has been\npopulated makes hdr_insert_head() memcpy attacker-controlled resident\nentry bytes past the end of the kmalloc(1u << indx->index_bits)\nallocation returned by indx_new(). For a 512-byte destination and a\nresident root whose non-last entries total 560 bytes, the memcpy\noverruns by 120 bytes and a following memmove extends the highest\nwritten offset to 136 bytes past the allocation. The overflow bytes\nare a direct copy of on-disk entries (via kmemdup), so they are\nfully attacker-controlled.\n\nThe write is reachable from unprivileged open(O_CREAT) on a mounted\ncrafted NTFS image: a single sufficiently long create in a directory\nwhose resident root is already full forces root promotion and\ntriggers the copy.\n\nThis is a controlled out-of-bounds write of 120-136 bytes past a\nkmalloc(index_block_size) allocation, with attacker-controlled\ncontent. It is a bounded adjacent-heap corruption primitive; it is\nnot an arbitrary-address write. Successful exploitation into a named\nvictim object depends on the surrounding slab layout.\n\nReject the copy at the sink. The destination's INDEX_HDR already\nreports hdr_total (the payload capacity of the new buffer) and\nhdr_used (the bytes already consumed by the terminal END entry\ninstalled by indx_new()); require that to_move fits in the remaining\npayload before calling hdr_insert_head(). On mismatch, fail with\n-EINVAL and mark the filesystem as having a detected on-disk\ninconsistency, which is the same behaviour as the surrounding\nvalidation in this function."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"0af83b8155cc848e9f5d2c36e20a70d024214649","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"cb3161deebcaf8d36d3115abf452c633f2180fc1","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"53c5f3b2da3774b41534728aba295c098c9efa19","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"194b00c99ba971fa7cf6acd747a36032c6de54eb","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"aaa1f956c0fc41089a4a534da7df91552a08a47c","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"d240f5f9d036b8180224954d9873f172b6be4dd8","versionType":"git"},{"version":"82cae269cfa953032fbb8980a7d554d60fb00b17","status":"affected","lessThan":"9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/index.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.15","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/index.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0af83b8155cc848e9f5d2c36e20a70d024214649"},{"url":"https://git.kernel.org/stable/c/cb3161deebcaf8d36d3115abf452c633f2180fc1"},{"url":"https://git.kernel.org/stable/c/53c5f3b2da3774b41534728aba295c098c9efa19"},{"url":"https://git.kernel.org/stable/c/194b00c99ba971fa7cf6acd747a36032c6de54eb"},{"url":"https://git.kernel.org/stable/c/aaa1f956c0fc41089a4a534da7df91552a08a47c"},{"url":"https://git.kernel.org/stable/c/d240f5f9d036b8180224954d9873f172b6be4dd8"},{"url":"https://git.kernel.org/stable/c/9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - ntfs3 registers export_operations; on NAS/hybrid servers exporting an NTFS volume via nfsd or ksmbd, a remote client's CREATE reaches vfs_create→ntfs_create→ntfs_create_inode→indx_insert_entry→indx_insert_into_root without any local syscall from the attacker.\nAC:L - The attacker fully controls on-disk $INDEX_ROOT layout (resident entry sizes and index_block_size); a single create in a full resident directory deterministically forces root promotion and the unchecked hdr_insert_head() copy, with no races or victim-specific heap layout required to trigger the overflow.\nPR:N - Exploitation needs only write access to create a file in the target directory on an NFS/SMB-exported NTFS share (including guest/anonymous write), or supplying removable media later mounted by the host; no init-namespace root or CAP_SYS_ADMIN is required on the trigger path.\nUI:N - Once an administrator has mounted and optionally exported the NTFS volume—or desktop/kiosk automount has attached removable media—the attacker issues open(O_CREAT)/touch/mkdir directly; no further victim clicks, file opens, or cooperative actions beyond that standing configuration are required.\nS:U - Impact is attacker-controlled kernel heap corruption and panic within the host kernel's security authority; this is standard local or network filesystem exploitation, not a VM escape, IOMMU bypass, or cross-scope sandbox breakout.\nC:H - hdr_insert_head() memcpy/memmove writes 120-136 attacker-controlled bytes past the kzalloc(1u<