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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
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.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-89471 being exploited?
There is no known exploitation of CVE-2026-89471 in the wild and no public exploit code.
Sources
Also known as AZL-100199, BELL-CVE-2026-89471, DEBIAN-CVE-2026-89471, GHSA-543c-r37x-r759, UBUNTU-CVE-2026-89471.