CVE-2026-74574 dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()
A race condition in the Linux kernel idxd driver causes a deadlock and use-after-free during device open failures, leading to system denial of service.
- 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-2026-74574?
CVE-2026-74574 is a high-severity vulnerability in Linux, published on 15 Aug 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:
dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()
The failed_dev_add and failed_dev_name paths drop the file-device reference while wq->wq_lock is still held. If put_device(fdev) drops the last reference, idxd_file_dev_release() runs synchronously and tries to take wq->wq_lock again, deadlocking.
Those paths also fall through into the later ctx cleanup labels even though idxd_file_dev_release() owns that cleanup and frees ctx. This can make idxd_xa_pasid_remove(ctx) and kfree(ctx) operate on a freed context.
Move idxd_wq_get() before file-device setup can fail, since the release callback always calls idxd_wq_put(). Then unlock wq->wq_lock before put_device(fdev) and return directly from the file-device setup failure path, leaving ctx cleanup to the release callback.
Which versions are affected by CVE-2026-74574?
How do I fix CVE-2026-74574?
Apply the vendor's patch.
Is CVE-2026-74574 being exploited?
There is no known exploitation of CVE-2026-74574 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74574, DEBIAN-CVE-2026-74574, GHSA-6vf2-r72r-2pc8, UBUNTU-CVE-2026-74574.