---
id: CVE-2026-10679
title: >-
  Divide-by-zero in DesignWare SPI driver reachable from spi_transceive syscall
  (local DoS)
summary: >-
  The DesignWare SPI driver (drivers/spi/spi_dw.c) computed the SPI BAUDR clock
  divider as info->clock_frequency / config->frequency without validating
  config->frequency.


  spi_transceive is a Zephyr __syscall and its verify handler (driver…
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-369
vendor: zephyrproject
product: zephyr
affected:
  - zephyr >= 1.8.0 < 4.3.1
  - zephyr >= 4.4.0 < 4.4.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-22T19:32:22.710575Z'
published: '2026-07-21'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:10:18.522Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-10679'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/commit/65935885622b0e4a5dbe5b82504c30097eb75ce0
    label: Fix commit
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3qcm-qwh2-v4hq
    label: GHSA-3qcm-qwh2-v4hq
tags:
  - cve.org
epss: 0.00136
epssPercentile: 0.02668
ingestedAt: '2026-10-15T22:48:25.573Z'
---

## Overview

The DesignWare SPI driver (drivers/spi/spi_dw.c) computed the SPI BAUDR clock divider as info->clock_frequency / config->frequency without validating config->frequency.

spi_transceive is a Zephyr __syscall and its verify handler (drivers/spi/spi_handlers.c) copies the caller-supplied spi_config from userspace without checking the frequency field, so a userspace thread that has been granted access to a DesignWare SPI device kernel object can pass frequency = 0 and trigger an unsigned integer divide-by-zero in spi_dw_configure().

On Cortex-M Mainline (SCB->CCR.DIV_0_TRP is set in z_arm_fault_init()) and on ARC (a dedicated __ev_div_zero vector) this raises a CPU exception, resulting in a kernel fault and local denial of service.

The fix rejects zero frequency and frequencies above clock_frequency / 2 (the DesignWare SSI databook minimum SCKDIV of 2) with -EINVAL. The defect affects all Zephyr releases up to and including v4.4.0; exploitation requires CONFIG_USERSPACE=y and an unprivileged thread already granted SPI driver permission. There is no memory-corruption or information-disclosure impact.

## Affected

- `zephyr >= 1.8.0 < 4.3.1`
- `zephyr >= 4.4.0 < 4.4.2`

## Remediation

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