# CVE-2026-46022: misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()

> A compromised service processor can trigger an out-of-bounds MMIO read in the ibmasm driver, causing a machine check exception and system crash.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 27 May 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-88587, BELL-CVE-2026-46022, DEBIAN-CVE-2026-46022, GHSA-cpgx-54rr-4jm6, ROOT-OS-DEBIAN-11-CVE-2026-46022, ROOT-OS-DEBIAN-12-CVE-2026-46022, ROOT-OS-UBUNTU-2204-CVE-2026-46022, ROOT-OS-UBUNTU-2404-CVE-2026-46022, UBUNTU-CVE-2026-46022

## What is CVE-2026-46022?

CVE-2026-46022 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 May 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:

misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()

ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read
when the queue reader or writer index from hardware exceeds
REMOTE_QUEUE_SIZE (60).

A compromised service processor can trigger this by writing an
out-of-range value to the reader or writer MMIO register before
asserting an interrupt. Since writer is re-read from hardware on
every loop iteration, it can also be set to an out-of-range value
after the loop has already started.

The root cause is that get_queue_reader() and get_queue_writer() return
raw readl() values that are passed directly into get_queue_entry(),
which computes:

  queue_begin + reader * sizeof(struct remote_input)

with no bounds check. This unchecked MMIO address is then passed to
memcpy_fromio(), reading 8 bytes from unintended device registers.
For sufficiently large values the address falls outside the PCI BAR
mapping entirely, triggering a machine check exception.

Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of
the loop body, before any call to get_queue_entry(). On an out-of-range
value, reset the reader register to 0 via set_queue_reader() before
breaking, so that normal queue operation can resume if the corrupted
hardware state is transient.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-46022?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46022?

Apply the vendor's patch.

## Is CVE-2026-46022 being exploited?

There is no known exploitation of CVE-2026-46022 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-2026-46022 and fix it if it is affected.

What it is: CVE-2026-46022 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 May 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-2026-46022 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-2026-46022/ (Markdown: https://insights.sbomify.com/CVE-2026-46022/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46022
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46022
- OSV: https://osv.dev/vulnerability/CVE-2026-46022

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46022/
Summaries are generated and may contain mistakes; the official description above is the record.