# CVE-2026-52948: i2c: dev: prevent integer overflow in I2C_TIMEOUT ioctl

> A local attacker can trigger an integer overflow in the I2C_TIMEOUT ioctl, causing SMBus state machine corruption and 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:** 24 Jun 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-90513, BELL-CVE-2026-52948, DEBIAN-CVE-2026-52948, GHSA-rj5f-9xf7-69h7, ROOT-OS-DEBIAN-11-CVE-2026-52948, ROOT-OS-DEBIAN-12-CVE-2026-52948, ROOT-OS-UBUNTU-2204-CVE-2026-52948, ROOT-OS-UBUNTU-2404-CVE-2026-52948, UBUNTU-CVE-2026-52948

## What is CVE-2026-52948?

CVE-2026-52948 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 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:

i2c: dev: prevent integer overflow in I2C_TIMEOUT ioctl

While fuzzing with Syzkaller, a persistent `schedule_timeout: wrong
timeout value` warning was observed, accompanied by SMBus controller
state machine corruption.

The I2C_TIMEOUT ioctl accepts a user-provided timeout in multiples of
10 ms. The user argument is checked against INT_MAX, but it is
subsequently multiplied by 10 before being passed to msecs_to_jiffies().

A malicious user can pass a large value (e.g., 429496729) that passes
the `arg > INT_MAX` check but overflows when multiplied by 10. This
results in a truncated 32-bit unsigned value that bypasses the
internal `(int)m < 0` check in `msecs_to_jiffies()`.

The truncated value is then assigned to `client->adapter->timeout`
(a signed 32-bit int), which is reinterpreted as a negative number.
When passed to wait_for_completion_timeout(), this negative value
undergoes sign extension to a 64-bit unsigned long, triggering the
`schedule_timeout` warning and causing premature returns. This leaves
the SMBus state machine in an unrecoverable state, constituting a
local Denial of Service (DoS).

Fix this by bounding the user argument to `INT_MAX / 10`.

[wsa: move the comment as well]

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-52948?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52948?

Apply the vendor's patch.

## Is CVE-2026-52948 being exploited?

There is no known exploitation of CVE-2026-52948 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-2026-52948 and fix it if it is affected.

What it is: CVE-2026-52948 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 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-2026-52948 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-2026-52948/ (Markdown: https://insights.sbomify.com/CVE-2026-52948/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52948
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52948
- OSV: https://osv.dev/vulnerability/CVE-2026-52948

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52948/
Summaries are generated and may contain mistakes; the official description above is the record.