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

Q: Is CVE-2026-97619 being exploited?

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

Not scored Published 25 Sep 2026 Updated 21 Oct 2026

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.

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

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.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-97619 being exploited?