{"cve":"CVE-2025-21726","nvd":{"published":"2025-02-27T02:15:16.323","modified":"2026-10-15T02:17:30.520","status":"Modified","description":"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<kworker context>\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<kworker context>\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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/4c6209efea2208597dbd3e52dc87a0d1a8f2dbe1","https://git.kernel.org/stable/c/6f45ef616775b0ce7889b0f6077fc8d681ab30bc","https://git.kernel.org/stable/c/7000507bb0d2ceb545c0a690e0c707c897d102c2","https://git.kernel.org/stable/c/8ca38d0ca8c3d30dd18d311f1a7ec5cb56972cac","https://git.kernel.org/stable/c/a54091c24220a4cd847d5b4f36d678edacddbaf0"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2025-21726","score":0.00236,"percentile":0.14397,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}