CVE-2024-50070 in Linux
Summary
by MITRE • 10/29/2024
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: stm32: check devm_kasprintf() returned value
devm_kasprintf() can return a NULL pointer on failure but this returned value is not checked. Fix this lack and check the returned value.
Found by code review.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/21/2025
The vulnerability identified as CVE-2024-50070 resides within the Linux kernel's pinctrl subsystem, specifically affecting the stm32 driver implementation. This issue represents a classic null pointer dereference scenario that could potentially lead to system instability or denial of service conditions. The vulnerability manifests in the stm32 pinctrl driver where the devm_kasprintf() function is utilized to dynamically allocate and format strings for device management purposes. The function devm_kasprintf() serves as a memory management helper that combines the functionality of kasprintf with device management, automatically handling memory cleanup during device removal. However, the driver implementation fails to validate the return value of this function call, creating a potential crash scenario when memory allocation fails.
The technical flaw stems from insufficient error handling in the device management code path. When devm_kasprintf() encounters memory allocation failure, it returns NULL instead of a valid string pointer, but the calling code does not check for this condition. This pattern violates fundamental defensive programming practices and creates a direct path for system instability. The vulnerability is categorized under CWE-476 as a NULL pointer dereference, where the system fails to properly validate function return values before using them. The root cause lies in the code review process that identified this oversight, highlighting the importance of thorough static analysis and code review practices in kernel development.
The operational impact of this vulnerability extends beyond simple system crashes, potentially affecting embedded systems and devices that rely heavily on the stm32 pinctrl driver for hardware pin configuration. In production environments, particularly those involving automotive systems, industrial controls, or IoT devices using stm32 processors, this vulnerability could result in unexpected device failures or complete system lockups. The vulnerability affects systems where device management operations are critical for proper hardware initialization and configuration, making it particularly concerning for embedded Linux deployments. Attackers could potentially exploit this by triggering memory allocation failures in specific scenarios, leading to denial of service conditions that might be difficult to recover from without manual intervention.
Mitigation strategies for CVE-2024-50070 involve implementing proper error checking after devm_kasprintf() calls within the stm32 pinctrl driver. The fix requires adding validation checks to ensure that the returned pointer from devm_kasprintf() is not NULL before proceeding with subsequent operations. This approach aligns with the ATT&CK framework's defensive techniques for preventing code injection and memory corruption attacks. System administrators should prioritize applying kernel updates that contain the patched version of the stm32 pinctrl driver, as this vulnerability affects the core kernel functionality. Additionally, implementing comprehensive testing procedures that include memory allocation failure scenarios would help prevent similar issues in other kernel subsystems. The fix demonstrates the importance of adhering to kernel development best practices and maintaining robust error handling throughout all code paths, particularly in device management and memory allocation functions that are critical for system stability.