CVE-2024-35822 addresses a vulnerability in the Linux kernel's USB gadget subsystem, specifically within the mass storage function driver. The issue arises when the mass storage function attempts to queue a USB endpoint request from the main thread while another thread may have already disabled the endpoint (ep). This race condition triggers a warning message in the kernel logs: "WARNING: CPU: X PID: Y at drivers/usb/gadget/udc/core.c:294 usb_ep_queue+0x7c/0x104". The root cause is that the mass storage function does not properly synchronize access to the USB endpoint queue, leading to attempts to queue requests on endpoints that have been disabled concurrently by another thread. The fix implemented changes the kernel's behavior from raising a WARN_ON_ONCE() warning to a pr_debug() message, effectively suppressing the warning without altering the underlying driver logic. This indicates that the issue does not cause functional failure or crashes but may lead to noisy kernel logs and potential confusion during debugging or monitoring. No direct exploitation or security compromise is indicated, and no known exploits exist in the wild. The vulnerability affects specific Linux kernel versions identified by the commit hash 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2. The vulnerability is primarily a race condition in USB gadget mass storage function handling and does not impact the confidentiality, integrity, or availability of the system directly.

For European organizations, the impact of CVE-2024-35822 is minimal from a security perspective. Since the vulnerability does not cause driver failure or system crashes and only results in kernel warning messages, it does not present a direct risk of data breach, privilege escalation, or denial of service. However, organizations using Linux devices that implement USB gadget mass storage functions—such as embedded systems, IoT devices, or specialized USB peripherals—may experience increased kernel log noise, which could complicate system monitoring and troubleshooting. In environments with strict logging and alerting policies, these warnings might generate false positives or obscure other critical events. The vulnerability does not appear to be exploitable remotely or without local access, limiting its threat scope. Consequently, the operational impact is low, but awareness is important for system administrators to avoid unnecessary alarm and to maintain clean system logs.

To mitigate CVE-2024-35822, European organizations should: 1) Apply the latest Linux kernel updates that include the fix changing WARN_ON_ONCE() to pr_debug() in the usb_ep_queue() function. This update reduces kernel log noise without altering driver functionality. 2) Review and adjust system monitoring and alerting configurations to filter or suppress these specific USB gadget warnings if kernel updates cannot be immediately applied. 3) For embedded or specialized devices using USB gadget mass storage, coordinate with device vendors to ensure firmware or kernel patches are applied promptly. 4) Implement robust testing and validation of kernel updates in controlled environments before deployment to avoid unintended side effects. 5) Maintain awareness of USB gadget usage in their infrastructure and document any custom drivers or kernel modules that may interact with USB endpoints to facilitate rapid response if related issues arise.