# 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.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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 Jul 2026
- **Updated:** 17 Aug 2026
- **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

## 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 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-64292?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64292?

Apply the vendor's patch.

## 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

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64292 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-64292 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-64292/ (Markdown: https://insights.sbomify.com/CVE-2026-64292/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64292
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64292
- OSV: https://osv.dev/vulnerability/CVE-2026-64292

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64292/
Summaries are generated and may contain mistakes; the official description above is the record.