{"id":"CVE-2026-17052","title":"The Time-aware GPIO syscall verification handler z_vrfy_tgpio_pin_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_handlers.c validated only the port device object and passed the caller-supplied timestamp and event_count output poin…","summary":"The Time-aware GPIO syscall verification handler z_vrfy_tgpio_pin_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_handlers.c validated only the port device object and passed the caller-supplied timestamp and event_count output poin…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787"],"vendor":"zephyrproject","product":"zephyr","affected":["zephyr >= 3.5.0 < 4.4.2"],"published":"2026-09-21","updated":"2026-09-21","sourceUpdated":"2026-09-21T19:17:04.080","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-17052","references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/26264fffc17c2174319394ffa274af3f6efdc221","label":"vulnerabilities@zephyrproject.org"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8qw6-x76h-8mpc","label":"vulnerabilities@zephyrproject.org"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-21T18:42:55.294194Z"},"ingestedAt":"2026-09-21T18:50:57.567Z","slug":"CVE-2026-17052","body":"## Overview\n\nThe Time-aware GPIO syscall verification handler z_vrfy_tgpio_pin_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_handlers.c validated only the port device object and passed the caller-supplied timestamp and event_count output pointers to the driver without a K_SYSCALL_MEMORY_WRITE() check. The other handlers in the same file (z_vrfy_tgpio_port_get_time(), z_vrfy_tgpio_port_get_cycles_per_second()) already performed that check, so the omission left one syscall unguarded.\n\ntgpio_pin_read_ts_ec() is declared __syscall, so with CONFIG_USERSPACE=y an unprivileged user-mode thread that has been granted access to the TGPIO device object can invoke it with arbitrary pointer values. tgpio_intel_read_ts_ec() in drivers/timeaware_gpio/timeaware_gpio_intel.c bounds-checks only the pin index and then unconditionally performs timestamp = ... and event_count = ..., executing two 8-byte stores in supervisor mode at addresses chosen by the user-mode caller.\n\nThe result is a write-what-where primitive that crosses the userspace/kernel boundary: the target address is fully attacker-chosen and the stored values are the hardware time-capture and event-counter register contents. Corrupting kernel data structures this way can escalate the calling thread to supervisor privilege or crash the system; the device-object permission required is a narrow capability that is not intended to confer any kernel-memory access. The fix adds the two missing K_SYSCALL_MEMORY_WRITE() validations before the driver call.\n\nExposure is narrow in practice. Only builds with CONFIG_USERSPACE=y and CONFIG_TIMEAWARE_GPIO=y compile the affected file, and from v3.6.0 onward the file additionally referenced a relocated header (<zephyr/syscall_handler.h>) and removed Z_SYSCALL_* macros, so such a configuration failed to build until those were repaired after v4.4.0. Downstream trees that locally corrected that breakage, and v3.5.0 builds where it did not exist, are the exposed population.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}