{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-49983", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T12:17:06.053Z", "datePublished": "2024-10-21T18:02:28.474Z", "dateUpdated": "2026-08-05T11:40:52.589Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:40:52.589Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free\n\nWhen calling ext4_force_split_extent_at() in ext4_ext_replay_update_ex(),\nthe 'ppath' is updated but it is the 'path' that is freed, thus potentially\ntriggering a double-free in the following process:\n\next4_ext_replay_update_ex\n ppath = path\n ext4_force_split_extent_at(&ppath)\n ext4_split_extent_at\n ext4_ext_insert_extent\n ext4_ext_create_new_leaf\n ext4_ext_grow_indepth\n ext4_find_extent\n if (depth > path[0].p_maxdepth)\n kfree(path) ---> path First freed\n *orig_path = path = NULL ---> null ppath\n kfree(path) ---> path double-free !!!\n\nSo drop the unnecessary ppath and use path directly to avoid this problem.\nAnd use ext4_find_extent() directly to update path, avoiding unnecessary\nmemory allocation and freeing. Also, propagate the error returned by\next4_find_extent() instead of using strange error codes." } ], "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 only entry point is `mount(2)` on a locally-attached block device holding an ext4 image whose journal carries an unreplayed fast-commit area; `ext4_ext_replay_update_ex()` has no callers outside `ext4_fc_replay_add_range()`, so there is no network- or adjacent-reachable path.\nAC:L - The attacker authors the entire image, so the extent-tree depth, the ADD_RANGE records and the corrupted extent block that makes the inner `ext4_find_extent()` fail are all chosen deterministically — no race and no memory-layout dependency outside attacker control, and standard slab grooming decides what reclaims the freed `kmalloc-N` object.\nPR:L - ext4 lacks `FS_USERNS_MOUNT` so `mount(2)` itself wants CAP_SYS_ADMIN, but an ordinary local user reaches the identical replay path by attaching removable media that udisks2/autofs mounts automatically, or via a `user` fstab entry — the standard crafted-ext4-image threat model on kiosks, workstations and embedded devices.\nUI:N - The attacker performs the mount themselves, either directly or by inserting media whose automount is unattended, so no action by a separate victim user is needed.\nS:U - The freed object, the stale dereferences and the corrupted slab freelist all live in the kernel's own memory and security authority; no hypervisor, IOMMU or sandbox boundary is crossed.\nC:H - `ext4_free_ext_path()` on the dangling pointer reads `p_depth` and every `p_bh` field back out of the already-freed, potentially reclaimed slab object, so attacker-groomed content is dereferenced as `struct buffer_head *` — a use-after-free read that yields arbitrary kernel-memory disclosure and kernel address leaks.\nI:H - The double `kfree()` corrupts the SLUB freelist, allowing the same chunk to be handed out twice and later overwritten, and the intervening `brelse()`/`put_bh()` decrements a refcount at an attacker-influenced address — together a controlled write primitive leveragable for control-flow hijack and privilege escalation.\nA:H - Even unexploited, a double-free plus dereference of freed `struct ext4_ext_path` entries reliably trips slab corruption detection or oopses in `brelse()` during mount, panicking the machine, and the mount can be repeated at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/extents.c" ], "versions": [ { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "8c26d9e53e5fbacda0732a577e97c5a5b7882aaf", "status": "affected", "versionType": "git" }, { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "a34bed978364114390162c27e50fca50791c568d", "status": "affected", "versionType": "git" }, { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "6367d3f04c69e2b8770b8137bd800e0784b0abbc", "status": "affected", "versionType": "git" }, { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "1b558006d98b7b0b730027be0ee98973dd10ee0d", "status": "affected", "versionType": "git" }, { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "3ff710662e8d86a63a39b334e9ca0cb10e5c14b0", "status": "affected", "versionType": "git" }, { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "63adc9016917e6970fb0104ee5fd6770f02b2d80", "status": "affected", "versionType": "git" }, { "version": "8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2", "lessThan": "5c0f4cc84d3a601c99bc5e6e6eb1cbda542cce95", "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/extents.c" ], "versions": [ { "version": "5.10", "status": "affected" }, { "version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.227", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.168", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.113", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.55", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.10.14", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.3", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "5.10", "versionEndExcluding": "5.10.227" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.15.168" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.1.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.6.55" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.10.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.11.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/8c26d9e53e5fbacda0732a577e97c5a5b7882aaf" }, { "url": "https://git.kernel.org/stable/c/a34bed978364114390162c27e50fca50791c568d" }, { "url": "https://git.kernel.org/stable/c/6367d3f04c69e2b8770b8137bd800e0784b0abbc" }, { "url": "https://git.kernel.org/stable/c/1b558006d98b7b0b730027be0ee98973dd10ee0d" }, { "url": "https://git.kernel.org/stable/c/3ff710662e8d86a63a39b334e9ca0cb10e5c14b0" }, { "url": "https://git.kernel.org/stable/c/63adc9016917e6970fb0104ee5fd6770f02b2d80" }, { "url": "https://git.kernel.org/stable/c/5c0f4cc84d3a601c99bc5e6e6eb1cbda542cce95" } ], "title": "ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-49983", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-10-22T13:32:15.569255Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-22T13:38:44.023Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:24:05.400Z" } } ] } }