CVE-2025-38286 in Linux
Summary
by MITRE • 07/10/2025
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: at91: Fix possible out-of-boundary access
at91_gpio_probe() doesn't check that given OF alias is not available or something went wrong when trying to get it. This might have consequences when accessing gpio_chips array with that value as an index. Note, that BUG() can be compiled out and hence won't actually perform the required checks.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/19/2025
The vulnerability identified as CVE-2025-38286 represents a critical out-of-bounds memory access flaw within the Linux kernel's pinctrl subsystem, specifically affecting the at91 platform driver implementation. This issue stems from insufficient validation during the GPIO chip initialization process where the at91_gpio_probe() function fails to properly verify the availability and correctness of device tree OF aliases before utilizing them as array indices. The root cause lies in the absence of proper bounds checking mechanisms that should validate the integrity of the device tree alias information prior to memory access operations, creating a potential pathway for unauthorized memory access patterns that could compromise system stability and security.
The technical exploitation of this vulnerability occurs when the kernel attempts to access the gpio_chips array using an invalid or improperly validated index derived from a device tree alias. This flaw directly relates to CWE-129, which encompasses improper validation of array indices, and represents a classic case of insufficient input validation that can lead to memory corruption. The vulnerability is particularly concerning because the BUG() macro, which should provide runtime protection against such conditions, can be compiled out during kernel build processes, meaning that the protective checks are not always present in production systems. This compilation-time dependency creates a scenario where the vulnerability remains undetected and exploitable in systems where the debug assertions have been disabled.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially enabling attackers to manipulate kernel memory structures and compromise the integrity of the system's GPIO subsystem. The at91 platform driver, which handles GPIO operations for Atmel AT91 microcontrollers, becomes vulnerable to malicious input through device tree configurations that provide invalid aliases. This could allow for privilege escalation scenarios where an attacker with access to device tree modifications or system configuration could potentially execute arbitrary code within kernel space, leading to complete system compromise. The vulnerability affects systems running Linux kernels that utilize the at91 pinctrl driver and are configured to use device tree alias mechanisms for GPIO chip identification.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation within the at91_gpio_probe() function to ensure proper verification of device tree aliases before array access operations. System administrators should ensure that kernel versions containing the fix are deployed across affected systems, as the vulnerability exists in the core kernel subsystem that handles hardware abstraction layers. The recommended approach involves adding explicit bounds checking and error handling mechanisms that validate the alias values against expected ranges and verify their availability within the system configuration. Additionally, organizations should implement device tree validation procedures to prevent the introduction of malformed alias configurations that could trigger this vulnerability, aligning with security best practices outlined in the ATT&CK framework for kernel-level privilege escalation techniques and hardware abstraction layer manipulation.