| Name | CVE-2026-46274 |
| Description | In the Linux kernel, the following vulnerability has been resolved: io-wq: check that the predecessor is hashed in io_wq_remove_pending() io_wq_remove_pending() needs to fix up wq->hash_tail[] if the cancelled work was the tail of its hash bucket. When doing this, it checks whether the preceding entry in acct->work_list has the same hash value, but never checks that the predecessor is hashed at all. io_get_work_hash() is simply atomic_read(&work->flags) >> IO_WQ_HASH_SHIFT, and the hash bits are never set for non-hashed work, so it returns 0. Thus, when a hashed bucket-0 work is cancelled while a non-hashed work is its list predecessor, the check spuriously passes and a pointer to the non-hashed io_kiocb is stored in wq->hash_tail[0]. Because non-hashed work is dequeued via the fast path in io_get_next_work(), which never touches hash_tail[], the stale pointer is never cleared. Therefore, after the non-hashed io_kiocb completes and is freed back to req_cachep, wq->hash_tail[0] is a dangling pointer. The io_wq is per-task (tctx->io_wq) and survives ring open/close, so the dangling pointer persists for the lifetime of the task; the next hashed bucket-0 enqueue dereferences it in io_wq_insert_work() and wq_list_add_after() writes through freed memory. Add the missing io_wq_is_hashed() check so a non-hashed predecessor never inherits a hash_tail[] slot. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-6355-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| linux (PTS) | bullseye | 5.10.223-1 | vulnerable |
| bullseye (security) | 5.10.257-1 | vulnerable |
| bookworm | 6.1.170-3 | vulnerable |
| bookworm (security) | 6.1.174-1 | vulnerable |
| trixie | 6.12.86-1 | vulnerable |
| trixie (security) | 6.12.94-1 | fixed |
| forky, sid | 7.0.13-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| linux | source | trixie | 6.12.94-1 | DSA-6355-1 |
| linux | source | (unstable) | 7.0.10-1 |
Notes
https://git.kernel.org/linus/d6a2d7b04b5a093021a7a0e2e69e9d5237dfa8cc (7.1-rc4)
