{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-49956", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T12:17:06.048Z", "datePublished": "2024-10-21T18:02:10.385Z", "dateUpdated": "2026-08-05T11:40:40.767Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:40:40.767Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: fix double destroy_workqueue error\n\nWhen gfs2_fill_super() fails, destroy_workqueue() is called within\ngfs2_gl_hash_clear(), and the subsequent code path calls\ndestroy_workqueue() on the same work queue again.\n\nThis issue can be fixed by setting the work queue pointer to NULL after\nthe first destroy_workqueue() call and checking for a NULL pointer\nbefore attempting to destroy the work queue again." } ], "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 vulnerability is reached only through the local mount path (`get_tree_bdev` → `gfs2_fill_super`) acting on a block device or image file present on the system. There is no network-facing consumer of this code.\nAC:L - Any `gfs2_fill_super()` failure at or after `init_locking()` deterministically reaches the double `destroy_workqueue()`; a crafted image that passes `gfs2_check_sb()` but fails in `init_sb()` triggers it on every attempt with no race or memory-layout precondition. syzbot produced a reliable reproducer.\nPR:N - The attacker needs no privileges on the target — they only supply the malformed GFS2 image (removable media, downloaded image file, or attacker-controlled shared/SAN storage). The privilege for the mount itself belongs to the victim, not the attacker.\nUI:R - A privileged user or an automount/storage-management daemon must mount the attacker-supplied GFS2 volume for `gfs2_fill_super()` to run and fail.\nS:U - The corruption is confined to kernel memory and kernel workqueue state within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The second `destroy_workqueue()` runs on a freed `workqueue_struct`, reading `flags`, `rescuer`, `pwqs`, and `cpu_pwq` from memory an attacker can reclaim via heap spraying, and using those values to drive kfree/kthread/list operations — a use-after-free read primitive leading to kernel memory disclosure.\nI:H - The use-after-free yields write primitives into the reclaimed object — `wq->flags |= __WQ_DESTROYING`, `list_del_rcu(&wq->list)` writing through attacker-influenced `prev`/`next` pointers, plus `kfree(wq->wq_dev)` and `kfree(rescuer)` on controlled pointers — sufficient for heap manipulation and control-flow hijack.\nA:H - Even absent reallocation, the second `list_del_rcu()` corrupts the global `workqueues` list and dereferences `LIST_POISON2`, producing a guaranteed kernel oops/panic; workqueue-core corruption also destabilizes the whole system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/gfs2/glock.c", "fs/gfs2/ops_fstype.c" ], "versions": [ { "version": "30e388d573673474cbd089dec83688331c117add", "lessThan": "a5336035728d77efd76306940d742a6f23debe68", "status": "affected", "versionType": "git" }, { "version": "30e388d573673474cbd089dec83688331c117add", "lessThan": "6cb9df81a2c462b89d2f9611009ab43ae8717841", "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/gfs2/glock.c", "fs/gfs2/ops_fstype.c" ], "versions": [ { "version": "6.11", "status": "affected" }, { "version": "0", "lessThan": "6.11", "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": "6.11", "versionEndExcluding": "6.11.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a5336035728d77efd76306940d742a6f23debe68" }, { "url": "https://git.kernel.org/stable/c/6cb9df81a2c462b89d2f9611009ab43ae8717841" } ], "title": "gfs2: fix double destroy_workqueue error", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-49956", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-10-22T13:35:44.463461Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-22T13:38:48.390Z" } } ] } }