{"cve":"CVE-2026-46274","nvd":{"published":"2026-06-08T16:16:40.707","modified":"2026-07-23T07:10:00.113","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio-wq: check that the predecessor is hashed in io_wq_remove_pending()\n\nio_wq_remove_pending() needs to fix up wq->hash_tail[] if the cancelled\nwork was the tail of its hash bucket. When doing this, it checks whether\nthe preceding entry in acct->work_list has the same hash value, but\nnever checks that the predecessor is hashed at all. io_get_work_hash()\nis simply atomic_read(&work->flags) >> IO_WQ_HASH_SHIFT, and the hash\nbits are never set for non-hashed work, so it returns 0. Thus, when a\nhashed bucket-0 work is cancelled while a non-hashed work is its list\npredecessor, the check spuriously passes and a pointer to the non-hashed\nio_kiocb is stored in wq->hash_tail[0].\n\nBecause non-hashed work is dequeued via the fast path in\nio_get_next_work(), which never touches hash_tail[], the stale pointer\nis never cleared. Therefore, after the non-hashed io_kiocb completes and\nis freed back to req_cachep, wq->hash_tail[0] is a dangling pointer. The\nio_wq is per-task (tctx->io_wq) and survives ring open/close, so the\ndangling pointer persists for the lifetime of the task; the next hashed\nbucket-0 enqueue dereferences it in io_wq_insert_work() and\nwq_list_add_after() writes through freed memory.\n\nAdd the missing io_wq_is_hashed() check so a non-hashed predecessor\nnever inherits a hash_tail[] slot.","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/252c5051dba9c709b6a72f2866f93e5e618b3f06","https://git.kernel.org/stable/c/5a20ebf0c81b61f5ea3b1b529c100cad69b9f603","https://git.kernel.org/stable/c/d376c131af7c7739a87ff037ed2fdb67c2542c8a","https://git.kernel.org/stable/c/d6a2d7b04b5a093021a7a0e2e69e9d5237dfa8cc","https://git.kernel.org/stable/c/d6bda9df0c0a3080804181464d5c0f4d78a4e769"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-46274","score":0.00138,"percentile":0.03161,"date":"2026-10-31"},"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."]}