{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53626", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-07T15:16:59.656Z", "datePublished": "2025-10-07T15:19:30.895Z", "dateUpdated": "2026-08-05T09:15:11.541Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:15:11.541Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix possible double unlock when moving a directory" } ], "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 through the `rename(2)` syscall on a locally mounted ext4 filesystem; no network or remote peer is involved. The attacker needs local access to mount/attach the crafted ext4 image and issue the rename.\nAC:L - The `ext4_rename_dir_prepare()` failure is deterministic with a crafted `.`/`..` entry, so the double `up_write()` always occurs, and the attacker controls every thread contending for the moved directory's `i_rwsem`. The unlock window spans a sleeping `ext4_journal_stop()`, so winning the mutual-exclusion-break race is easy and infinitely retryable.\nPR:L - An ordinary unprivileged local user suffices: on mainstream desktop/kiosk deployments udisks2's default polkit `allow_active` loop-setup and removable-media automount let a console user mount an arbitrary attacker-authored ext4 image, and the `rename(2)` itself needs only write access to the attacker's own directories.\nUI:N - In the automount/loop-setup scenario the attacker performs the mount and the rename themselves; no second user has to be induced into any action.\nS:U - The corrupted `i_rwsem`, the resulting concurrent directory mutation, and any memory corruption all stay within the kernel's own security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - Breaking exclusion on a directory inode lets concurrent readers/writers race the inline-dir-to-extent conversion, so dirent parsing runs against the raw inode's `i_block`/xattr region under a stale format assumption, exposing adjacent kernel memory through `readdir`/`getdents`, and the buffer_head UAF this enables gives a further read primitive.\nI:H - The silent release of another task's exclusive `i_rwsem` allows two threads to run ext4 dirent add/delete, htree split, and inline-to-extent conversion on the same inode simultaneously, producing metadata and heap corruption — the exact corruption class `0813299c586b` was written to prevent — which is leverageable for controlled writes.\nA:H - When the lock is free at the second unlock, the rwsem count underflows to `~0UL` with no owner, so every later `down_read`/`down_write` on that directory blocks permanently in uninterruptible sleep, hanging the directory, the unmount, and eventually tripping the hung-task watchdog. The corruption path independently yields oopses and `errors=remount-ro`/`panic` filesystem shutdown." } ] } ], "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": "8dac5a63cf79707b547ea3d425fead5f4482198f", "lessThan": "c16cbd8233d6c58fc488545393e49b5d55729990", "status": "affected", "versionType": "git" }, { "version": "0c440f14558bfacd22c6935ae1fd4b2a09e96b5d", "lessThan": "020166bc6669ca9fb267ebd96bd88c4fb64a5d46", "status": "affected", "versionType": "git" }, { "version": "c50fc503ee1b97f12c98e26afc39fdaebebcf04f", "lessThan": "1c93c42c7bb23057bde8a0a2ab834927ff64d20c", "status": "affected", "versionType": "git" }, { "version": "b0bb13612292ca90fa4c2a7e425375649bc50d3e", "lessThan": "e71eb4dca41f0f36823724ced0406bb2dbdd5506", "status": "affected", "versionType": "git" }, { "version": "291cd19d107e197306869cb3237c1bba62d13182", "lessThan": "43ce288ab5d7274a4a141d7f5e3ed2ab7b41f8a2", "status": "affected", "versionType": "git" }, { "version": "0813299c586b175d7edb25f56412c54b812d0379", "lessThan": "70e42feab2e20618ddd0cbfc4ab4b08628236ecd", "status": "affected", "versionType": "git" } ] }, { "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": "5.4.237", "lessThan": "5.4.238", "status": "affected", "versionType": "semver" }, { "version": "5.10.175", "lessThan": "5.10.176", "status": "affected", "versionType": "semver" }, { "version": "5.15.103", "lessThan": "5.15.104", "status": "affected", "versionType": "semver" }, { "version": "6.1.20", "lessThan": "6.1.21", "status": "affected", "versionType": "semver" }, { "version": "6.2.7", "lessThan": "6.2.8", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.237", "versionEndExcluding": "5.4.238" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.175", "versionEndExcluding": "5.10.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.103", "versionEndExcluding": "5.15.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.20", "versionEndExcluding": "6.1.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2.7", "versionEndExcluding": "6.2.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c16cbd8233d6c58fc488545393e49b5d55729990" }, { "url": "https://git.kernel.org/stable/c/020166bc6669ca9fb267ebd96bd88c4fb64a5d46" }, { "url": "https://git.kernel.org/stable/c/1c93c42c7bb23057bde8a0a2ab834927ff64d20c" }, { "url": "https://git.kernel.org/stable/c/e71eb4dca41f0f36823724ced0406bb2dbdd5506" }, { "url": "https://git.kernel.org/stable/c/43ce288ab5d7274a4a141d7f5e3ed2ab7b41f8a2" }, { "url": "https://git.kernel.org/stable/c/70e42feab2e20618ddd0cbfc4ab4b08628236ecd" } ], "title": "ext4: fix possible double unlock when moving a directory", "x_generator": { "engine": "bippy-1.2.0" } } } }