---
id: CVE-2026-89471
title: 'power: supply: cros_usbpd-charger: bound the EC-reported port count'
summary: |-
  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_port…
severity: high
cvss: 8.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-787
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    0b5096f6804161b61451b1cec0e38678630be849
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    c46c9f447415ca802afab51dea1eafc08ddff1c6
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    a1905375dfc0b9612bbee52fc066e3a70c0d671d
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    2746d502b12b343384fb747bdef9cbcfbd7444a2
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    fd29d08ee487f3bf50f2575aaa74f78a74b09b21
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    78be8b7403ff7638162438b664a07d19da76059e
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    3d1e01443b221081258ff34ea0cdd0431e4ff62e
  - >-
    Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed <
    48355ce49359740f52e94d3623f6fc557ce341f0
  - Linux 4.19
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:47:20.319Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89471'
references:
  - url: 'https://git.kernel.org/stable/c/0b5096f6804161b61451b1cec0e38678630be849'
  - url: 'https://git.kernel.org/stable/c/c46c9f447415ca802afab51dea1eafc08ddff1c6'
  - url: 'https://git.kernel.org/stable/c/a1905375dfc0b9612bbee52fc066e3a70c0d671d'
  - url: 'https://git.kernel.org/stable/c/2746d502b12b343384fb747bdef9cbcfbd7444a2'
  - url: 'https://git.kernel.org/stable/c/fd29d08ee487f3bf50f2575aaa74f78a74b09b21'
  - url: 'https://git.kernel.org/stable/c/78be8b7403ff7638162438b664a07d19da76059e'
  - url: 'https://git.kernel.org/stable/c/3d1e01443b221081258ff34ea0cdd0431e4ff62e'
  - url: 'https://git.kernel.org/stable/c/48355ce49359740f52e94d3623f6fc557ce341f0'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89471.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89471'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532398'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89471'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89471'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89471.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00142
epssPercentile: 0.03449
scores:
  cna: 8.4
  vendor: 5.5
ingestedAt: '2026-09-14T15:23:07.453Z'
---

## Overview

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.

## Affected

- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < 0b5096f6804161b61451b1cec0e38678630be849`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < c46c9f447415ca802afab51dea1eafc08ddff1c6`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < a1905375dfc0b9612bbee52fc066e3a70c0d671d`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < 2746d502b12b343384fb747bdef9cbcfbd7444a2`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < fd29d08ee487f3bf50f2575aaa74f78a74b09b21`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < 78be8b7403ff7638162438b664a07d19da76059e`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < 3d1e01443b221081258ff34ea0cdd0431e4ff62e`
- `Linux >= f68b883e8fad23ed0ac4756d91594809d78678ed < 48355ce49359740f52e94d3623f6fc557ce341f0`
- `Linux 4.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89471.json)