CVE-2026-68374 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
usb: core: sysfs: add lock to bos_descriptors_read()
Add a lock to the function bos_descriptors_read().
This function accesses udev->bos, which could be simultaneously freed in usb_reset_and_verify_device(), a function that is commonly called in drivers all over the kernel.
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Analysis
by VulDB Data Team • 08/10/2026
The vulnerability identified in the Linux kernel represents a critical race condition affecting the USB subsystem's sysfs interface. This flaw manifests in the bos_descriptors_read() function within the USB core module, where concurrent access to the udev->bos data structure creates potential for memory corruption and system instability. The issue arises from insufficient synchronization mechanisms protecting shared resources during concurrent operations, specifically when the function attempts to read from udev->bos while another kernel thread may simultaneously be executing usb_reset_and_verify_device() which can free this same memory region.
The technical implementation of this vulnerability stems from improper locking mechanisms within the USB subsystem's sysfs interface implementation. When multiple threads attempt to access the bos descriptors through sysfs while the device reset process is underway, the lack of proper mutex or spinlock protection allows for a classic race condition scenario. The udev->bos structure serves as a shared resource between the read operation and the device reset function, creating a window where memory deallocation can occur during active reading operations. This type of vulnerability falls under CWE-362, which specifically addresses race conditions in concurrent programming environments.
The operational impact of this vulnerability extends beyond simple memory corruption to potentially enable privilege escalation and system instability across various Linux distributions utilizing the affected kernel versions. Attackers could exploit this condition by triggering concurrent access patterns that force the system into a state where freed memory is accessed, potentially leading to denial of service conditions or more severe exploitation scenarios. The widespread use of USB drivers throughout the kernel ecosystem means that any process calling usb_reset_and_verify_device() creates a potential attack vector for this race condition, making it particularly dangerous in multi-threaded environments where USB devices are frequently accessed and reset.
The mitigation strategy involves implementing proper locking mechanisms around the bos_descriptors_read() function to ensure exclusive access to the udev->bos structure during read operations. This solution aligns with ATT&CK technique T1068 which covers privilege escalation through kernel vulnerabilities, ensuring that such race conditions cannot be exploited by malicious actors. The fix requires adding appropriate synchronization primitives such as mutex locks or spinlocks to protect the shared resource access, preventing simultaneous read and write operations on the udev->bos structure. This approach addresses the fundamental flaw by ensuring atomic access to critical kernel data structures while maintaining system performance through minimal locking overhead.
The implementation of this fix demonstrates adherence to secure coding practices recommended in industry standards such as those outlined in the Linux Kernel Security documentation, where proper locking mechanisms are essential for protecting shared resources in multi-threaded kernel environments. The solution specifically targets the root cause by ensuring that any access to udev->bos during device reset operations is properly synchronized, preventing memory corruption that could lead to system crashes or unauthorized privilege escalation. This vulnerability resolution exemplifies the importance of proper resource management and synchronization in kernel-level programming where race conditions can have severe security implications across the entire operating system stack.
The broader implications of this fix extend to the overall stability and security posture of Linux systems utilizing USB functionality, particularly in server environments where concurrent device access is common. The patch ensures that USB subsystem operations maintain integrity during concurrent access patterns while preserving expected functionality for legitimate use cases. This type of vulnerability resolution is critical for maintaining kernel security boundaries and preventing exploitation scenarios that could compromise the entire system through indirect attacks on core kernel subsystems. The solution represents a defensive programming approach that aligns with both CWE best practices for race condition prevention and ATT&CK framework recommendations for mitigating kernel-level privilege escalation vectors through proper synchronization mechanisms.