# CVE-2026-23085: irqchip/gic-v3-its: Avoid truncating memory addresses

> An integer truncation in the Linux kernel GICv3 ITS driver can cause a system crash on 32-bit ARM systems with LPAE enabled.

- **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:** 4 Feb 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-77217, BELL-CVE-2026-23085, DEBIAN-CVE-2026-23085, GHSA-v2xc-c9fw-v73w, OESA-2026-1469, OESA-2026-1470, ROOT-OS-UBUNTU-2204-CVE-2026-23085, ROOT-OS-UBUNTU-2404-CVE-2026-23085, UBUNTU-CVE-2026-23085

## What is CVE-2026-23085?

CVE-2026-23085 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 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:

irqchip/gic-v3-its: Avoid truncating memory addresses

On 32-bit machines with CONFIG_ARM_LPAE, it is possible for lowmem
allocations to be backed by addresses physical memory above the 32-bit
address limit, as found while experimenting with larger VMSPLIT
configurations.

This caused the qemu virt model to crash in the GICv3 driver, which
allocates the 'itt' object using GFP_KERNEL. Since all memory below
the 4GB physical address limit is in ZONE_DMA in this configuration,
kmalloc() defaults to higher addresses for ZONE_NORMAL, and the
ITS driver stores the physical address in a 32-bit 'unsigned long'
variable.

Change the itt_addr variable to the correct phys_addr_t type instead,
along with all other variables in this driver that hold a physical
address.

The gicv5 driver correctly uses u64 variables, while all other irqchip
drivers don't call virt_to_phys or similar interfaces. It's expected that
other device drivers have similar issues, but fixing this one is
sufficient for booting a virtio based guest.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-23085?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23085?

Apply the vendor's patch.

## Is CVE-2026-23085 being exploited?

There is no known exploitation of CVE-2026-23085 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-2026-23085 and fix it if it is affected.

What it is: CVE-2026-23085 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 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-2026-23085 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-2026-23085/ (Markdown: https://insights.sbomify.com/CVE-2026-23085/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23085
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23085
- OSV: https://osv.dev/vulnerability/CVE-2026-23085

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23085/
Summaries are generated and may contain mistakes; the official description above is the record.