{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49343", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T02:08:31.542Z", "datePublished": "2025-02-26T02:10:59.970Z", "dateUpdated": "2026-08-05T08:54:50.163Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:54:50.163Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: avoid cycles in directory h-tree\n\nA maliciously corrupted filesystem can contain cycles in the h-tree\nstored inside a directory. That can easily lead to the kernel corrupting\ntree nodes that were already verified under its hands while doing a node\nsplit and consequently accessing unallocated memory. Fix the problem by\nverifying traversed block numbers are unique." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only through local VFS directory operations on a mounted crafted ext4 image (creat/mkdir → ext4_add_entry → ext4_dx_add_entry → dx_probe → do_split/index split); there is no network or adjacent-protocol entry into fs/ext4/namei.c.\nAC:L - The attacker fully controls on-disk h-tree block pointers, so a cyclic index (e.g. an intermediate node pointing back to an ancestor) deterministically makes dx_probe load the same block at multiple frame levels and then corrupts those nodes on split; no race or attacker-uncontrollable layout is required.\nPR:N - The attacker needs no account on the target—only a malicious ext4 image (USB/SD, disk image, or media handed to udisks/automount); ext4 is FS_REQUIRES_DEV without FS_USERNS_MOUNT, so CAP_SYS_ADMIN for mount belongs to the victim or automount path.\nUI:R - Exploitation requires a user or automount/storage daemon to mount the attacker-supplied ext4 volume and then perform a directory write that triggers an h-tree node split on the cyclic directory.\nS:U - Corruption and crashes remain within the host kernel’s buffer-cache/htree handling under the same OS security authority; this is standard local kernel impact, not a VM escape, IOMMU bypass, or other cross-boundary break.\nC:H - Node split on aliased frames corrupts already-verified index nodes and leads to accessing unallocated memory; that out-of-bounds/UAF-class read of kernel heap or freed buffers enables arbitrary disclosure and is scored Confidentiality High.\nI:H - The same split path (dx_insert_block/memmove and index-node rewrites through shared frame buffers) performs attacker-influenced writes into corrupted/unallocated memory, enabling heap corruption and control-flow hijack primitives scored Integrity High.\nA:H - Accessing unallocated memory during the split of a cyclic h-tree can oops/panic the kernel even without full exploitation, fully denying availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/namei.c" ], "versions": [ { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "24b8206fec1db21d7e82f21f0b2ff5e5672cf5b3", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "b3ad9ff6f06c1dc6abf7437691c88ca3d6da3ac0", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "e157c8f87e8fac112d6c955e69a60cdb9bc80a60", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "ff4cafa51762da3824881a9000ca421d4b78b138", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "3a3ce941645407cd0b0b7f01ad9e2ea3770f46cc", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "d5a16a6df2c16eaf4de04948553ef0089dee463f", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "6084240bfc44bf265ab6ae7d96980469b05be0f1", "status": "affected", "versionType": "git" }, { "version": "ac27a0ec112a089f1a5102bc8dffc79c8c815571", "lessThan": "3ba733f879c2a88910744647e41edeefbc0d92b2", "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/ext4/namei.c" ], "versions": [ { "version": "2.6.19", "status": "affected" }, { "version": "0", "lessThan": "2.6.19", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.283", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.247", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.198", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.121", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.46", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.14", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18.3", "lessThanOrEqual": "5.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.19", "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": "2.6.19", "versionEndExcluding": "4.14.283" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "4.19.247" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.4.198" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.10.121" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.15.46" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.17.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.18.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/24b8206fec1db21d7e82f21f0b2ff5e5672cf5b3" }, { "url": "https://git.kernel.org/stable/c/b3ad9ff6f06c1dc6abf7437691c88ca3d6da3ac0" }, { "url": "https://git.kernel.org/stable/c/e157c8f87e8fac112d6c955e69a60cdb9bc80a60" }, { "url": "https://git.kernel.org/stable/c/ff4cafa51762da3824881a9000ca421d4b78b138" }, { "url": "https://git.kernel.org/stable/c/3a3ce941645407cd0b0b7f01ad9e2ea3770f46cc" }, { "url": "https://git.kernel.org/stable/c/d5a16a6df2c16eaf4de04948553ef0089dee463f" }, { "url": "https://git.kernel.org/stable/c/6084240bfc44bf265ab6ae7d96980469b05be0f1" }, { "url": "https://git.kernel.org/stable/c/3ba733f879c2a88910744647e41edeefbc0d92b2" } ], "title": "ext4: avoid cycles in directory h-tree", "x_generator": { "engine": "bippy-1.2.0" } } } }