{"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"}}}}