CVE-2025-68312 usbnet: Prevents free active kevent
A use-after-free vulnerability in the Linux kernel usbnet driver allows local attackers to cause a system crash by triggering a race condition during device unregistration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68312?
CVE-2025-68312 is an use after free vulnerability in Linux, published on 16 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
usbnet: Prevents free active kevent
The root cause of this issue are: 1. When probing the usbnet device, executing usbnet_link_change(dev, 0, 0); put the kevent work in global workqueue. However, the kevent has not yet been scheduled when the usbnet device is unregistered. Therefore, executing free_netdev() results in the "free active object (kevent)" error reported here.
2. Another factor is that when calling usbnet_disconnect()->unregister_netdev(), if the usbnet device is up, ndo_stop() is executed to cancel the kevent. However, because the device is not up, ndo_stop() is not executed.
The solution to this problem is to cancel the kevent before executing free_netdev().
Which versions are affected by CVE-2025-68312?
How do I fix CVE-2025-68312?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-68312 being exploited?
There is no known exploitation of CVE-2025-68312 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68312, DEBIAN-CVE-2025-68312, GHSA-g57h-pwpg-2849, ROOT-OS-DEBIAN-12-CVE-2025-68312, ROOT-OS-DEBIAN-13-CVE-2025-68312, ROOT-OS-UBUNTU-2204-CVE-2025-68312 and 2 more.