# CVE-2026-63934: iio: gyro: itg3200: fix i2c read into the wrong stack location

> A local attacker can read uninitialized kernel stack memory via the ITG3200 gyroscope driver, potentially leaking sensitive information.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Jul 2026
- **Updated:** 19 Jul 2026
- **Also known as:** BELL-CVE-2026-63934, DEBIAN-CVE-2026-63934, GHSA-xvpq-5jw7-83gf, ROOT-OS-UBUNTU-2204-CVE-2026-63934, UBUNTU-CVE-2026-63934

## What is CVE-2026-63934?

CVE-2026-63934 is a vulnerability in Linux, published on 19 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:

iio: gyro: itg3200: fix i2c read into the wrong stack location

itg3200_read_all_channels() takes `__be16 *buf' as a parameter and
fills the i2c_msg destination as `(char *)&buf'. Since `buf' is the
parameter (a pointer), `&buf' is the address of the local pointer
slot on the stack of itg3200_read_all_channels(), not the address
of the caller's scan buffer. The (char *) cast hides the type
mismatch.

i2c_transfer() therefore writes ITG3200_SCAN_ELEMENTS * sizeof(s16)
= 8 bytes into the parameter's stack slot, which is discarded when
the function returns. The caller's scan buffer in
itg3200_trigger_handler() is never written to, so
iio_push_to_buffers_with_timestamp() pushes uninitialised stack
contents to userspace via /dev/iio:deviceX every scan -- both a
functional bug (no actual gyroscope or temperature data is
delivered through the triggered buffer) and an information leak.

The non-buffered read_raw() path is unaffected: it goes through
itg3200_read_reg_s16() which uses `&out' on a local s16 value,
where that is correct.

Drop the spurious `&' so the i2c read writes into the caller's
buffer.

## Which versions are affected by CVE-2026-63934?


## How do I fix CVE-2026-63934?

Apply the vendor's patch.

## Is CVE-2026-63934 being exploited?

There is no known exploitation of CVE-2026-63934 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63934 and fix it if it is affected.

What it is: CVE-2026-63934 is a vulnerability in Linux, published on 19 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-2026-63934 in the wild and no public exploit code.

Affected product: Linux. 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-2026-63934/ (Markdown: https://insights.sbomify.com/CVE-2026-63934/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63934
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63934
- OSV: https://osv.dev/vulnerability/CVE-2026-63934

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63934/
Summaries are generated and may contain mistakes; the official description above is the record.