{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72191", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.911Z", "datePublished": "2026-08-15T05:53:51.893Z", "dateUpdated": "2026-08-23T12:47:01.444Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:47:01.444Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: validate split-point offset in indx_insert_into_buffer\n\nindx_insert_into_buffer() computes\n\n used = used1 - to_copy - sp_size;\n memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));\n\nwhere sp and sp_size come from hdr_find_split(). hdr_find_split()\nwalks entries by le16_to_cpu(e->size) without validating that each\nstep stays within hdr->used or that the size field is at least\nsizeof(struct NTFS_DE). index_hdr_check(), the on-load gatekeeper,\nonly validates header-level fields (used, total, de_off) and does\nnot walk per-entry sizes.\n\nA crafted NTFS image whose leaf INDEX_HDR reports used == total but\ncontains one interior NTFS_DE with size = 0xFFF0 therefore passes\nvalidation, descends to indx_insert_into_buffer() through the\nntfs_create() -> indx_insert_entry() path, and makes hdr_find_split()\nreturn an sp whose sp_size (0xFFF0) greatly exceeds the remaining\nbytes in the buffer. The u32 subtraction underflows and the memmove\ncount becomes a near-4-GiB value, producing an out-of-bounds kernel\nwrite that corrupts adjacent allocations and panics the kernel.\n\nReproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a\nsingle 'touch' inside the mounted directory; crash site resolves to\nfs/ntfs3/index.c at the memmove. Trigger requires only local mount\nof an attacker-supplied filesystem image (USB, loopback, or removable\nmedia auto-mount).\n\nReject the split whenever the chosen sp plus its declared size\nalready extends past hdr1->used. This is the minimal fix; it\npreserves the existing hdr_find_split() contract and relies on the\nsame out: cleanup path as the pre-existing error returns.\n\nA prior OOB read in the very same indx_insert_into_buffer() memmove\nwas fixed in commit b8c44949044e (\"fs/ntfs3: Fix OOB read in\nindx_insert_into_buffer\") by tightening hdr_find_e(), but that fix\ndoes not cover the split-point size field path addressed here: sp is\nreturned by hdr_find_split(), not hdr_find_e(), and the underflow is\ndriven by sp->size rather than hdr->used exceeding hdr->total." } ], "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 - Remote SMB CREATE via ksmbd vfs_create on an ntfs3-exported share reaches ntfs_create_inode→indx_insert_entry→indx_insert_into_buffer; the same memmove path is also reachable locally via open(O_CREAT)/touch on a mounted crafted image.\nAC:L - The attacker fully controls the on-disk leaf INDEX_HDR and NTFS_DE size (e.g. 0xFFF0); once the buffer is full and a create forces a split, hdr_find_split() deterministically selects the bad entry and the u32 underflow yields a reliable near-4GiB OOB memmove with no race.\nPR:N - Exploitation requires only a crafted NTFS image and a create in the malicious directory—no root on the target—via udisks2/systemd automount of attacker USB media, or a remote ksmbd client with guest/anonymous write access to an already-mounted ntfs3 export.\nUI:N - After the crafted volume is mounted (automounter or admin), a single attacker-initiated touch/create or remote SMB CREATE in the prepared full directory triggers the split and OOB memmove without any further victim clicks, prompts, or confirmation.\nS:U - The OOB memmove corrupts kernel heap memory within the same host OS security domain as ntfs3; it can enable local privilege escalation but does not cross a VM/hypervisor, IOMMU, or container sandbox boundary.\nC:H - The underflowed memmove length reads far beyond the kmalloc'd index buffer from attacker-controlled on-disk bytes, giving a large out-of-bounds kernel heap read and disclosure/corruption primitive in addition to the write side.\nI:H - The same memmove performs a massive out-of-bounds kernel heap write of adjacent slab objects with attacker-influenced source data, enabling arbitrary memory corruption and potential control-flow hijack beyond a simple denial of service.\nA:H - Reproduced on 7.0.0-rc7 with KASAN: the oversized memmove corrupts adjacent allocations and panics the kernel at fs/ntfs3/index.c; even failed exploitation attempts typically cause oops or hard lockup from the unbounded copy." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs3/index.c" ], "versions": [ { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "8e4ba5a38c155bb3c1c11e63cd285b178cdb099e", "status": "affected", "versionType": "git" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "4c2f648139a0a86f4486170f72e24fedd4fae74e", "status": "affected", "versionType": "git" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "b232eb5c9fe11ec2368e9b565db69c724c35fbd2", "status": "affected", "versionType": "git" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "7bf74e6baf810fe325f111996496c678fc6e244f", "status": "affected", "versionType": "git" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "f3624cc069195001c88df7a291af215f2133ff2c", "status": "affected", "versionType": "git" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "1758a564b6ebe7f4a82f23c9851d1cae15549457", "status": "affected", "versionType": "git" }, { "version": "82cae269cfa953032fbb8980a7d554d60fb00b17", "lessThan": "f1df9d771df47aa40de6d70949c28720ae1e430d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs3/index.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "5.15.217" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8e4ba5a38c155bb3c1c11e63cd285b178cdb099e" }, { "url": "https://git.kernel.org/stable/c/4c2f648139a0a86f4486170f72e24fedd4fae74e" }, { "url": "https://git.kernel.org/stable/c/b232eb5c9fe11ec2368e9b565db69c724c35fbd2" }, { "url": "https://git.kernel.org/stable/c/7bf74e6baf810fe325f111996496c678fc6e244f" }, { "url": "https://git.kernel.org/stable/c/f3624cc069195001c88df7a291af215f2133ff2c" }, { "url": "https://git.kernel.org/stable/c/1758a564b6ebe7f4a82f23c9851d1cae15549457" }, { "url": "https://git.kernel.org/stable/c/f1df9d771df47aa40de6d70949c28720ae1e430d" } ], "title": "ntfs3: validate split-point offset in indx_insert_into_buffer", "x_generator": { "engine": "bippy-1.2.0" } } } }