# CVE-2026-72141: i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)

> A flaw in the Linux kernel i2c-imx driver causes the I2C bus to lock up when handling zero-length SMBus block reads, requiring a power cycle to recover.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-72141, DEBIAN-CVE-2026-72141, GHSA-m5rq-h5xv-g5g9, UBUNTU-CVE-2026-72141

## What is CVE-2026-72141?

CVE-2026-72141 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)

SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the
interrupt-driven block-read state machine rejects it as -EPROTO. Worse,
it returns without a NACK+STOP: the next receive cycle has already
started, so the target keeps holding SDA and the bus stays stuck until a
power cycle of this i2c controller.

Accept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to
2 so i2c_imx_isr_read_continue() emits STOP via its normal last-byte
path. The dummy byte is discarded; block-read callers only consume
buf[0..count-1].

Reading I2DR has likewise already armed the next byte on the
count > I2C_SMBUS_BLOCK_MAX error path, so NACK it (TXAK) before aborting
with -EPROTO; otherwise the failing transfer's STOP cannot complete and
the bus stays held.

The atomic path regressed earlier (v3.16) and is fixed separately; this
patch covers only the v6.13 state-machine rework.

## Which versions are affected by CVE-2026-72141?


## How do I fix CVE-2026-72141?

Apply the vendor's patch.

## Is CVE-2026-72141 being exploited?

There is no known exploitation of CVE-2026-72141 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72141 and fix it if it is affected.

What it is: CVE-2026-72141 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-72141 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-2026-72141/ (Markdown: https://insights.sbomify.com/CVE-2026-72141/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72141
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72141
- OSV: https://osv.dev/vulnerability/CVE-2026-72141

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72141/
Summaries are generated and may contain mistakes; the official description above is the record.