{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-82961",
        "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
        "state": "PUBLISHED",
        "assignerShortName": "zephyr",
        "dateReserved": "2026-08-31T13:10:32.703Z",
        "datePublished": "2026-10-28T16:58:58.927Z",
        "dateUpdated": "2026-10-28T16:58:58.927Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
                "shortName": "zephyr",
                "dateUpdated": "2026-10-28T16:58:58.927Z"
            },
            "title": "Unvalidated pin index in GPIO syscall handlers allows out-of-bounds kernel writes from user mode",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "The GPIO syscall handlers in drivers/gpio/gpio_handlers.c did not validate the pin argument supplied by a user-mode caller. z_vrfy_gpio_pin_configure(), z_vrfy_gpio_pin_get_config() and z_vrfy_gpio_pin_interrupt_configure() verified only the device object (K_SYSCALL_DRIVER_GPIO() / K_SYSCALL_OBJ()) and then passed the caller-supplied gpio_pin_t straight through to z_impl_gpio_pin_*() and on to the driver. The only pin check in include/zephyr/drivers/gpio.h was __ASSERT(gpio_port_pin_is_supported(cfg->port_pin_mask, pin), ...), which compiles to nothing unless CONFIG_ASSERT is enabled, so in a production build no check existed at all.\n\nGPIO drivers use pin as a shift count and as an array index on the documented assumption that it is a pin the controller supports. On STM32, for example, gpio_stm32_pin_interrupt_configure() turns pin into an EXTI line and stm32_gpio_intc_set_irq_callback() writes data->cb[line_num].cb and data->cb[line_num].data into a NUM_EXTI_LINES-entry array (default 16) in drivers/interrupt_controller/intc_gpio_stm32.c, guarded only by a compiled-out __ASSERT_NO_MSG(); the same function then reads exti_irq_table[line_num] and calls irq_enable() on the result. Other controllers index fixed-size per-pin configuration tables the same way — drivers/gpio/gpio_ite_it8xxx2_v2.c reads an MMIO base pointer out of wuc_base[8] with the caller's pin and performs a read-modify-write through it.\n\nThe issue is reachable only in builds with CONFIG_USERSPACE=y (the file is compiled under that symbol), by a user-mode thread that has been granted access to a GPIO device object. Such a grant is intended to authorize control of that port's pins; the missing validation instead lets the thread drive a supervisor-mode out-of-bounds write of a function pointer and an associated void * past a kernel .bss array, and out-of-bounds reads that feed irq_enable() and MMIO accesses — an escape from the user-mode sandbox that can lead to kernel memory corruption, arbitrary code execution, or a crash.\n\nThe fix validates pin against the controller's gpio_driver_config.port_pin_mask with gpio_port_pin_is_supported() in every pin-taking z_vrfy_ handler and returns -EINVAL otherwise, complemented by an unconditional pin >= GPIO_MAX_PINS_PER_PORT range check added to the shared z_impl_gpio_pin_*() inlines."
                }
            ],
            "affected": [
                {
                    "vendor": "zephyrproject",
                    "product": "zephyr",
                    "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
                    "packageName": "zephyr",
                    "defaultStatus": "unaffected",
                    "programFiles": [
                        "drivers/gpio/gpio_emul.c",
                        "drivers/gpio/gpio_handlers.c",
                        "include/drivers/gpio.h",
                        "include/zephyr/drivers/gpio.h"
                    ],
                    "programRoutines": [
                        {
                            "name": "z_vrfy_gpio_config"
                        },
                        {
                            "name": "z_vrfy_gpio_pin_configure"
                        },
                        {
                            "name": "z_vrfy_gpio_pin_get_config"
                        },
                        {
                            "name": "z_vrfy_gpio_pin_interrupt_configure"
                        }
                    ],
                    "versions": [
                        {
                            "version": "2.2.0",
                            "status": "affected",
                            "versionType": "semver",
                            "lessThanOrEqual": "4.4.2"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/commit/020e83e06b35e98a4a3c2354f67e5eee3f163363",
                    "name": "Fix commit 020e83e06b35",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/commit/d145faab7e3a8cea62a8fd7ed5f30ef73e762f59",
                    "name": "Fix commit d145faab7e3a",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/commit/c9641fa5bfec44892e0cf2d84f78c7c60fca8ad6",
                    "name": "Fix commit c9641fa5bfec",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/commit/d28a05d5de4420f27ba3de7b9e4442fa056d51de",
                    "name": "Fix commit d28a05d5de44",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4f2x-8qw8-jjgf",
                    "name": "GHSA-4f2x-8qw8-jjgf"
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "bounds",
                            "cweId": "CWE-787",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "x_generator": {
                "engine": "cvelib 1.8.0"
            }
        }
    }
}