CVE-2026-31732

In the Linux kernel, the following vulnerability has been resolved:

gpio: Fix resource leaks on errors in gpiochip_add_data_with_key()

Since commit aab5c6f20023 (gpio: set device type for GPIO chips), gdev->dev.release is unset. As a result, the reference count to gdev->dev isnt dropped on the error handling paths.

Drop the reference on errors.

Also reorder the instructions to make the error handling simpler. Now gpiochip_add_data_with_key() roughly looks like:

Some memory allocation. Go to ERR ZONE 1 on errors. device_initialize().

gpiodev_release() takes over the responsibility for freeing the resources of gdev->dev. The subsequent error handling paths shouldnt go through ERR ZONE 1 again which leads to double free.

Some initialization mainly on gdev. The rest of initialization. Go to ERR ZONE 2 on errors. Chip registration success and exit.

ERR ZONE 2. gpio_device_put() and exit. ERR ZONE 1.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/16fdabe143fce2cbf89139677728e17e21b46c28
• https://git.kernel.org/stable/c/f0cf9c7b7c281956cc0dec163132cd96f76e1d60
• https://git.kernel.org/stable/c/fb4584d2b324c522404c733c65840a1a6519ada8