{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21726", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.754Z", "datePublished": "2025-02-27T02:07:32.861Z", "dateUpdated": "2026-08-05T11:53:59.161Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:53:59.161Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npadata: avoid UAF for reorder_work\n\nAlthough the previous patch can avoid ps and ps UAF for _do_serial, it\ncan not avoid potential UAF issue for reorder_work. This issue can\nhappen just as below:\n\ncrypto_request\t\t\tcrypto_request\t\tcrypto_del_alg\npadata_do_serial\n ...\n padata_reorder\n // processes all remaining\n // requests then breaks\n while (1) {\n if (!padata)\n break;\n ...\n }\n\n\t\t\t\tpadata_do_serial\n\t\t\t\t // new request added\n\t\t\t\t list_add\n // sees the new request\n queue_work(reorder_work)\n\t\t\t\t padata_reorder\n\t\t\t\t queue_work_on(squeue->work)\n...\n\n\t\t\t\t\n\t\t\t\tpadata_serial_worker\n\t\t\t\t// completes new request,\n\t\t\t\t// no more outstanding\n\t\t\t\t// requests\n\n\t\t\t\t\t\t\tcrypto_del_alg\n\t\t\t\t\t\t\t // free pd\n\n\ninvoke_padata_reorder\n // UAF of pd\n\nTo avoid UAF for 'reorder_work', get 'pd' ref before put 'reorder_work'\ninto the 'serial_wq' and put 'pd' ref until the 'serial_wq' finish." } ], "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 vulnerable padata reorder machinery is driven through pcrypt, reached locally via AF_ALG (`algif_aead`) socket operations or local xfrm/IPsec setup, and the `pd` free is triggered by local crypto-netlink/CPU-hotplug activity. No remote peer can reach or free the `parallel_data` object, so the attack requires local system access.\nAC:L - The attacker controls both sides of the race — they submit an unbounded stream of concurrent pcrypt AEAD requests to keep `reorder_work` queued while simultaneously driving the shell/pd teardown, and `serial_wq` is allocated with `max_active=1`, so `reorder_work` is routinely stalled behind serial workers, widening the window. Repeated attempts in a tight loop make the race reliably winnable, as the LTP `pcrypt_aead01` reproducer for the sibling bug demonstrates.\nPR:L - An unprivileged local user can fully drive the parallel/serial request side with no capability check at all via `AF_ALG` `algif_aead` binding `pcrypt(rfc4106(gcm(aes)))`, and the pd-release side is reachable through `padata_replace()` on CPU hotplug (suspend/resume, which logind grants to active unprivileged sessions) as well as through crypto netlink. No root-only gate is required on the path that actually corrupts memory.\nUI:N - The attacker issues both the crypto requests and the teardown that frees `parallel_data` themselves; no victim must mount a filesystem, open a file, or take any other action.\nS:U - The use-after-free corrupts kernel heap memory and is exploited within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - After `pd` is freed and reclaimed by sprayed attacker data, `padata_reorder()` follows `pd->ps->pinst`, `pd->reorder_list`, `pd->squeue` and `pd->cpumask.pcpu` out of the freed object, giving an attacker-directed read primitive over arbitrary kernel memory and disclosure of kernel state.\nI:H - The same freed object yields write primitives — `spin_trylock_bh(&pd->lock)`, `refcount_inc(&pd->refcnt)`, `++pd->processed`, and especially `list_del_init()`/`list_add_tail()` through attacker-controlled `reorder_list`/`squeue` pointers, plus a controlled `workqueue_struct *` fed to `queue_work_on()` — which is exploitable for arbitrary write and control-flow hijack leading to privilege escalation.\nA:H - Even without successful heap grooming, dereferencing the freed `parallel_data` reliably produces a KASAN slab-use-after-free splat, spinlock corruption, and kernel oops/panic, taking the whole system down; the crash can be reproduced repeatedly." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/padata.c" ], "versions": [ { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "f4f1b1169fc3694f9bc3e28c6c68dbbf4cc744c0", "status": "affected", "versionType": "git" }, { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "4c6209efea2208597dbd3e52dc87a0d1a8f2dbe1", "status": "affected", "versionType": "git" }, { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "7000507bb0d2ceb545c0a690e0c707c897d102c2", "status": "affected", "versionType": "git" }, { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "6f45ef616775b0ce7889b0f6077fc8d681ab30bc", "status": "affected", "versionType": "git" }, { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "8ca38d0ca8c3d30dd18d311f1a7ec5cb56972cac", "status": "affected", "versionType": "git" }, { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "a54091c24220a4cd847d5b4f36d678edacddbaf0", "status": "affected", "versionType": "git" }, { "version": "bbefa1dd6a6d53537c11624752219e39959d04fb", "lessThan": "dd7d37ccf6b11f3d95e797ebe4e9e886d0332600", "status": "affected", "versionType": "git" }, { "version": "b4c8ed0bf977760a206997b6429a7ac91978f440", "status": "affected", "versionType": "git" }, { "version": "e43d65719527043f1ef79ecba9d4ede58cbc7ffe", "status": "affected", "versionType": "git" }, { "version": "5.4.19", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "5.5.3", "lessThan": "5.6", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/padata.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.76", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.13", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.2", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "5.6", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.6.76" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.12.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.13.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f4f1b1169fc3694f9bc3e28c6c68dbbf4cc744c0" }, { "url": "https://git.kernel.org/stable/c/4c6209efea2208597dbd3e52dc87a0d1a8f2dbe1" }, { "url": "https://git.kernel.org/stable/c/7000507bb0d2ceb545c0a690e0c707c897d102c2" }, { "url": "https://git.kernel.org/stable/c/6f45ef616775b0ce7889b0f6077fc8d681ab30bc" }, { "url": "https://git.kernel.org/stable/c/8ca38d0ca8c3d30dd18d311f1a7ec5cb56972cac" }, { "url": "https://git.kernel.org/stable/c/a54091c24220a4cd847d5b4f36d678edacddbaf0" }, { "url": "https://git.kernel.org/stable/c/dd7d37ccf6b11f3d95e797ebe4e9e886d0332600" } ], "title": "padata: avoid UAF for reorder_work", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2025-21726", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-27T17:58:10.478288Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T18:02:28.114Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:36:27.811Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T12:03:29.655Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html" } ] } ] } }