# CVE-2026-97619: io_uring/rw: end write accounting from ->ki_complete

> A local attacker can cause a system hang by triggering a deadlock in the Linux kernel's io_uring write accounting during filesystem freeze operations.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-104349, BELL-CVE-2026-97619, DEBIAN-CVE-2026-97619, GHSA-rr3w-gg4f-957r, UBUNTU-CVE-2026-97619

## What is CVE-2026-97619?

CVE-2026-97619 is a denial of service vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

io_uring/rw: end write accounting from ->ki_complete

Commit b000145e9907 moved both the fsnotify calls and the write
accounting out of the kiocb completion handler and into the
io_req_rw_complete() task_work. However, only the fsnotify part actually
needed to move as it may sleep. Ending the write accounting is just a
percpu_up_read() on the superblock writers sem.

Deferring it is a problem, because it makes dropping SB_FREEZE_WRITE
protection depend on the ring owner getting to running task_work. But
the task may be blocked in freeze_super(), causing it to never get to
that:

  task                             io-wq worker
  --------------------------------------------------------------
  io_write()
    io_kiocb_start_write()         (takes sb_writers, hidden from
                                    lockdep by __sb_writers_release)
    write_iter() -> -EIOCBQUEUED
  ioctl(FS_IOC_SHUTDOWN)
    bdev_freeze()
      freeze_super()
        percpu_down_write()        <- waits for the reader above
                                   io_write()
                                     kiocb_start_write()
                                       percpu_down_read()  <- queued
                                                              behind the
                                                              writer
  <bio completes>
    io_complete_rw()
      queues io_req_rw_complete()  <- never runs, task is in D state

End the write from io_complete_rw() instead, and leave only the fsnotify
calls in task_work.

## Which versions are affected by CVE-2026-97619?


## How do I fix CVE-2026-97619?

Apply the vendor's patch.

## Is CVE-2026-97619 being exploited?

There is no known exploitation of CVE-2026-97619 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97619 and fix it if it is affected.

What it is: CVE-2026-97619 is a denial of service vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-97619 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-97619/ (Markdown: https://insights.sbomify.com/CVE-2026-97619/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97619
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97619
- OSV: https://osv.dev/vulnerability/CVE-2026-97619

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97619/
Summaries are generated and may contain mistakes; the official description above is the record.