UBUNTU-CVE-2025-39925

In the Linux kernel, the following vulnerability has been resolved: can: j1939: implement NETDEVUNREGISTER notification handler syzbot is reporting unregisternetdevice: waiting for vcan0 to become free. Usage count = 2 problem, for j1939 protocol did not have NETDEVUNREGISTER notification handler...

CVE-2025-39925

CVE-2025-39925 affects the Linux kernel’s CAN J1939 implementation. The issue stems from the j1939 protocol not having a NETDEV_UNREGISTER notification handler, which meant that when a NETDEV_UNREGISTER event fires, the extra ref held by j1939_sk_bind() could prevent the net_device usage count fr...