{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72195", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.911Z", "datePublished": "2026-08-15T05:53:54.869Z", "dateUpdated": "2026-08-17T05:41:21.899Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:41:21.899Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: bound attr_off in UpdateResidentValue against data_off\n\nIn do_action()'s UpdateResidentValue case (fslog.c:3307),\nlrh->attr_off and lrh->redo_len come from the on-disk LRH.\nWhen they satisfy aoff + dlen < attr->res.data_off, the\nassignment\n\n\tattr->res.data_size = cpu_to_le32(aoff + dlen - data_off);\n\nunderflows to ~4 GiB (e.g. 0xFFFFFFF9 when aoff=0x10, dlen=1,\ndata_off=0x18). Subsequent code that reads attr->res.data_size\nto walk the resident attribute payload would then read up to\n4 GiB past the 1024-byte MFT record allocation.\n\nThe existing mi_enum_attr() defense in fs/ntfs3/record.c:287\ncatches the corrupted data_size on the next attribute walk\nand fails the mount, but only on the path that walks all\nattributes. A read site that picks an attribute by name and\nreads its data_size without re-validating is not covered.\nValidate aoff against data_off and asize at the source.\n\nReproduced under UML+KASAN on mainline 8d90b09e6741 via\npr_warn-only probe: with aoff=0x10 and data_off=0x18, the\npost-assignment data_size is 0xfffffff9 (mount then fails\nat -22 from mi_enum_attr).\n\n[almaz.alexandrovich@paragon-software.com: clang-formatted the changes]" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only when the kernel mounts an attacker-controlled NTFS volume and replays $LogFile via ntfs_loadlog_and_replay→log_replay→do_action(UpdateResidentValue); exploitation uses the local mount syscall on a block/loop device, not a network-facing kernel service.\nAC:L - The attacker fully controls malicious on-disk LRH fields (attr_off, redo_len, data) in $LogFile; triggering the data_size underflow is deterministic once the crafted volume is mounted, with no races or conditions outside attacker control.\nPR:L - Mounting ntfs3 requires CAP_SYS_ADMIN in the mount namespace; an unprivileged local attacker can obtain this via user namespaces (unshare -Ur) and loop-mount a crafted NTFS image, without real root in the initial user namespace.\nUI:N - No victim interaction is required when the attacker mounts their own malicious NTFS image in a user namespace; exploitation does not depend on another user plugging in media, opening a file, or performing an additional action.\nS:U - The vulnerability corrupts kernel heap metadata during filesystem journal replay on the mounting host; impact stays within the kernel's security authority and does not constitute a VM escape, sandbox escape, or cross-authority boundary change.\nC:H - Unsigned underflow sets attr->res.data_size to ~4 GiB; subsequent resident-attribute consumers that trust data_size can read far beyond the ~1 KiB kmalloc MFT record allocation, disclosing adjacent kernel heap memory.\nI:H - The underflow corrupts resident-attribute metadata and UpdateResidentValue memmove paths using attacker-controlled offsets can overwrite attribute headers and drive out-of-bounds writes during replay, enabling heap corruption suitable for control-flow hijacking.\nA:H - Malformed journal replay can trigger kernel faults (KASAN/oops) or abort mount; repeated mount attempts against the malicious image cause persistent denial of service on the affected system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ntfs3/fslog.c" ], "versions": [ { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "ab8761676d638c5be170aaf91b7ffdd451236616", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "53c12f178f584dc5f836ffe2782138a6e9348ed9", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "546518468e6c9ea469669eef78f8cc380ad6e2ca", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "97758fd9756b5f09e9ddc6a5f6a569041acc8421", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "50b5e83384e7fed3d11d18b79ff350e9d6d89861", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "a89c66674283a0293c0f266dc57087a6114371a3", "status": "affected", "versionType": "git" }, { "version": "b46acd6a6a627d876898e1c84d3f84902264b445", "lessThan": "d1570c48f49a693974d000251030370ee2e83539", "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/fslog.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "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": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.178" }, { "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/ab8761676d638c5be170aaf91b7ffdd451236616" }, { "url": "https://git.kernel.org/stable/c/53c12f178f584dc5f836ffe2782138a6e9348ed9" }, { "url": "https://git.kernel.org/stable/c/546518468e6c9ea469669eef78f8cc380ad6e2ca" }, { "url": "https://git.kernel.org/stable/c/97758fd9756b5f09e9ddc6a5f6a569041acc8421" }, { "url": "https://git.kernel.org/stable/c/50b5e83384e7fed3d11d18b79ff350e9d6d89861" }, { "url": "https://git.kernel.org/stable/c/a89c66674283a0293c0f266dc57087a6114371a3" }, { "url": "https://git.kernel.org/stable/c/d1570c48f49a693974d000251030370ee2e83539" } ], "title": "fs/ntfs3: bound attr_off in UpdateResidentValue against data_off", "x_generator": { "engine": "bippy-1.2.0" } } } }