CVE-2025-68287: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-68287 is a race condition vulnerability in the Linux kernel's USB DWC3 (DesignWare USB3) controller driver that can lead to use-after-free conditions and potential kernel memory corruption. The flaw was published on December 16, 2025, and affects the Linux kernel where multiple unsynchronized execution paths concurrently invoke dwc3_remove_requests(), causing premature freeing of USB requests. It carries a CVSS v3.1 base score of 7.0 (High), reflecting a local attack vector with high complexity and low privilege requirements (Red Hat CVE, Microsoft MSRC).

The root cause is a race condition (CWE-362) combined with a use-after-free (CWE-416) in the dwc3_remove_requests() function of the Linux kernel's USB DWC3 driver. Three distinct execution paths can concurrently access and free USB request structures without proper synchronization: Path 1 is triggered via dwc3_gadget_reset_interrupt() through dwc3_ep0_reset_state() → dwc3_ep0_stall_and_restart() → dwc3_ep0_out_start() → dwc3_remove_requests(); Path 2 also originates from dwc3_gadget_reset_interrupt() but through dwc3_stop_active_transfers(); and Path 3 occurs asynchronously during USB function unbind/bind operations (e.g., adb root), traversing gserial_disconnect() → usb_ep_disable() → dwc3_gadget_ep_disable() → dwc3_remove_requests() with -ESHUTDOWN status. When Path 3 completes and frees 'out' requests while Paths 1 or 2 are still processing them, accessing the freed memory results in kernel crashes or memory corruption (Red Hat CVE).

Successful exploitation can cause system instability, kernel memory corruption, denial of service through system crashes, and potentially arbitrary code execution or privilege escalation. A local attacker with low privileges could trigger the race condition by manipulating USB device interactions (e.g., initiating adb root or USB reset events) to corrupt kernel memory. The confidentiality, integrity, and availability impacts are all rated High, meaning a successful exploit could expose sensitive kernel memory, corrupt data, or crash the system entirely (Red Hat CVE).

The Linux kernel community has developed a patch that adds checks for request completion and improves synchronization between the different dwc3_remove_requests() processing paths. Patches are available in the stable kernel tree (commits 7cfb62888eba, 47de14d741cc, 467add9db132, 67192e8cb7f9). Downstream vendors including Red Hat (RHSA-2026:0453, RHSA-2026:0457, RHSA-2026:0489, RHSA-2026:0537, RHSA-2026:0576, RHSA-2026:0793), Debian (DLA-4436-1), and Ubuntu (USN-8094-x, USN-8096-x, USN-8152-1) have released updated kernel packages. Recommended actions include: applying the latest kernel security update for your distribution, restricting local access to trusted users, monitoring and limiting USB device interactions, and keeping all system software and firmware up-to-date (Red Hat CVE, Microsoft MSRC).