CVE-2026-64292 iommufd: Move vevent memory allocation outside spinlock
A local attacker can exhaust kernel atomic memory reserves by allocating large IOMMU event queues, causing a 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-2026-64292?
CVE-2026-64292 is a medium-severity denial of service vulnerability in Linux kernel, published on 25 Jul 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:
iommufd: Move vevent memory allocation outside spinlock
The veventq memory allocation happens inside the spinlock. Given its depth is decided by the user space, this leaves a vulnerability, where userspace can allocate large queues to exhaust atomic memory reserves.
Move the allocation outside the spinlock and use GFP_NOWAIT, which can fail fast under memory pressure without dipping into the GFP_ATOMIC reserves or direct-reclaiming from the threaded IRQ handler. On allocation failure, queue the lost_events_header (so userspace learns of the drop) and return -ENOMEM so the caller learns of the kernel-side memory pressure.
This is intentionally distinct from the queue-overflow path, which also queues the lost_events_header but returns 0: a full queue is an expected userspace-pacing condition rather than a kernel error.
A subsequent change will cap the upper bound of the veventq_depth.
Weakness: CWE-401
Which versions are affected by CVE-2026-64292?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64292?
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-2026-64292 being exploited?
There is no known exploitation of CVE-2026-64292 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64292, DEBIAN-CVE-2026-64292, GHSA-gr72-p8g3-6gpc, ROOT-OS-UBUNTU-2204-CVE-2026-64292, UBUNTU-CVE-2026-64292.