# CVE-2026-89471

## Summary

- **CVE ID:** CVE-2026-89471
- **Severity:** HIGH
- **CVSS Score:** 8.4 (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## 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.

## Affected Products

- Linux — Linux (f68b883e8fad23ed0ac4756d91594809d78678ed)
- Linux — Linux (4.19)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/fd29d08ee487f3bf50f2575aaa74f78a74b09b21)
- [CNA](https://git.kernel.org/stable/c/78be8b7403ff7638162438b664a07d19da76059e)
- [CNA](https://git.kernel.org/stable/c/3d1e01443b221081258ff34ea0cdd0431e4ff62e)
- [CNA](https://git.kernel.org/stable/c/48355ce49359740f52e94d3623f6fc557ce341f0)
- [CNA](https://git.kernel.org/stable/c/0b5096f6804161b61451b1cec0e38678630be849)
- [CNA](https://git.kernel.org/stable/c/c46c9f447415ca802afab51dea1eafc08ddff1c6)
- [CNA](https://git.kernel.org/stable/c/a1905375dfc0b9612bbee52fc066e3a70c0d671d)
- [CNA](https://git.kernel.org/stable/c/2746d502b12b343384fb747bdef9cbcfbd7444a2)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.14%
- **EPSS Percentile:** 4.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._