{"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.\n\nspi_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","slug":"CVE-2026-10679","body":"## Overview\n\nThe DesignWare SPI driver (drivers/spi/spi_dw.c) computed the SPI BAUDR clock divider as info->clock_frequency / config->frequency without validating config->frequency.\n\nspi_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().\n\nOn 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.\n\nThe 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.\n\n## Affected\n\n- `zephyr >= 1.8.0 < 4.3.1`\n- `zephyr >= 4.4.0 < 4.4.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":18,"depthScoreParts":{"impact":18.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}