CVE-2026-43432

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

usb: xhci: Fix memory leak in xhci_disable_slot()

xhci_alloc_command() allocates a command structure and, when the second argument is true, also allocates a completion structure. Currently, the error handling path in xhci_disable_slot() only frees the command structure using kfree(), causing the completion structure to leak.

Use xhci_free_command() instead of kfree(). xhci_free_command() correctly frees both the command structure and the associated completion structure. Since the command structure is allocated with zero-initialization, command->in_ctx is NULL and will not be erroneously freed by xhci_free_command().

This bug was found using an experimental static analysis tool we are developing. The tool is based on the LLVM framework and is specifically designed to detect memory management issues. It is currently under active development and not yet publicly available, but we plan to open-source it after our research is published.

The bug was originally detected on v6.13-rc1 using our static analysis tool, and we have verified that the issue persists in the latest mainline kernel.

We performed build testing on x86_64 with allyesconfig using GCC=11.4.0. Since triggering these error paths in xhci_disable_slot() requires specific hardware conditions or abnormal state, we were unable to construct a test case to reliably trigger these specific error paths at runtime.

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/078b446efc0f5e496c31bccb72b98af979963a83
• https://git.kernel.org/stable/c/1e800e26d54ccf2ddf2ea6d6cbe021c804d8aa62
• https://git.kernel.org/stable/c/2e2baa8fb5aa4d080cbfeb84c51eff797529f413
• https://git.kernel.org/stable/c/46aea90763832cd6e9b0c2e1c00e6a9512156d4b
• https://git.kernel.org/stable/c/6288baf0c8c4dcfbf206773aede9c1f2269cec28
• https://git.kernel.org/stable/c/807e4fb5140c73eb5dba1e399a990db5c1f3cdf8
• https://git.kernel.org/stable/c/c1c8550e70401159184130a1afc6261db01fc0ce
• https://git.kernel.org/stable/c/c65f1b840ab8ce72ba68f1b63bab7960f8fdfa89