# CVE-2026-89471: power: supply: cros_usbpd-charger: bound the EC-reported port count

> A malicious or compromised Embedded Controller can trigger a slab out-of-bounds write in the ChromeOS USBPD charger driver, potentially leading to kernel code execution.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-100199, BELL-CVE-2026-89471, DEBIAN-CVE-2026-89471, GHSA-543c-r37x-r759, UBUNTU-CVE-2026-89471

## What is CVE-2026-89471?

CVE-2026-89471 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 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:

power: supply: cros_usbpd-charger: bound the EC-reported port count

cros_usbpd_charger_probe() reads two port counts from the EC and uses
one of them, num_charger_ports, as the loop bound when populating a
fixed-size array:

	struct port_data *ports[EC_USB_PD_MAX_PORTS];	/* 8 entries */
	...
	for (i = 0; i < charger->num_charger_ports; i++)
		charger->ports[charger->num_registered_psy++] = port;

Both num_usbpd_ports (from EC_CMD_USB_PD_PORTS) and num_charger_ports
(from EC_CMD_CHARGE_PORT_COUNT) are u8 values reported by the EC. The
only validation is a sanity check that compares the two EC-reported
values against each other:

	if (num_charger_ports < num_usbpd_ports ||
	    num_charger_ports > num_usbpd_ports + 1)
		return -EPROTO;

It never checks either count against EC_USB_PD_MAX_PORTS, the size of
the ports[] array. A malfunctioning, malicious or compromised EC that
reports num_usbpd_ports == num_charger_ports == N for any N > 8 (for
example both 255) passes this check, and the loop then writes N pointers
into the 8-entry ports[] array embedded in the devm_kzalloc()'d
charger_data, overflowing it by up to 255 - 8 = 247 entries (~1976
bytes): a slab out-of-bounds write.

Reject a port count larger than the ports[] array can hold.

## Which versions are affected by CVE-2026-89471?


## How do I fix CVE-2026-89471?

Apply the vendor's patch.

## Is CVE-2026-89471 being exploited?

There is no known exploitation of CVE-2026-89471 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89471 and fix it if it is affected.

What it is: CVE-2026-89471 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 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-2026-89471 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-2026-89471/ (Markdown: https://insights.sbomify.com/CVE-2026-89471/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89471
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89471
- OSV: https://osv.dev/vulnerability/CVE-2026-89471

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89471/
Summaries are generated and may contain mistakes; the official description above is the record.