CVE-2026-68410 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: libertas: fix memory leak in helper_firmware_cb()
helper_firmware_cb() neglects to free the single-stage firmware image after a successful async load, leading to a memory leak in the USB firmware-download path.
Fix this memory leak by calling release_firmware() immediately after lbs_fw_loaded() returns.
The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in the current wireless tree.
An x86_64 allyesconfig build showed no new warnings. As we do not have compatible Libertas USB hardware for exercising this firmware-download path, no runtime testing was able to be performed.
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Analysis
by VulDB Data Team • 08/10/2026
The vulnerability resides within the Linux kernel's wireless subsystem, specifically in the libertas driver implementation that manages wireless network adapters. This issue manifests as a memory leak during the asynchronous firmware loading process for USB-based wireless devices. The problem occurs when the helper_firmware_cb() function handles firmware callbacks but fails to properly release memory resources after a successful firmware download operation. The technical flaw represents a classic memory management oversight where allocated kernel memory remains unreleased, creating a persistent resource drain that could accumulate over time and potentially impact system stability.
The operational impact of this vulnerability extends beyond simple memory consumption as it demonstrates a fundamental failure in the kernel's resource lifecycle management for wireless device drivers. According to CWE-401, this represents a memory leak condition where the system fails to release allocated memory blocks after their intended use period. The flaw specifically affects the USB firmware-download path, which is critical for initializing wireless network adapters during system boot or device reconnection events. When multiple firmware downloads occur sequentially, each instance of the bug contributes to progressive memory consumption that could eventually degrade system performance or contribute to out-of-memory conditions.
The fix implementation addresses this through proper resource management by ensuring that release_firmware() is called immediately after lbs_fw_loaded() returns control to the calling function. This follows established kernel development practices for firmware handling and aligns with ATT&CK technique T1547.001 related to system service modifications where proper cleanup of resources is essential. The vulnerability was identified through automated analysis tools designed specifically to detect kernel memory management issues, highlighting the importance of systematic code analysis approaches in modern security research. While no runtime testing could be performed due to hardware limitations, the static analysis approach demonstrates how sophisticated tooling can identify latent security issues before they manifest in production environments.
The absence of new warnings in the x86_64 allyesconfig build indicates that the fix maintains kernel compilation integrity without introducing regressions or additional complexity. However, the lack of actual hardware testing means this vulnerability remains unverified in real-world scenarios, which underscores the need for comprehensive testing strategies including both automated analysis and physical hardware validation. The vulnerability's presence in the wireless tree suggests potential for similar issues in other driver implementations that handle asynchronous firmware loading operations, making this fix not just a localized patch but a pattern of proper resource management that should be applied across related subsystems. This memory leak represents a subtle but significant degradation risk that could accumulate over extended system uptime periods and potentially impact mobile or embedded devices where memory resources are more constrained.