NetSight
medium5.5

CVE-2025-71182

In the Linux kernel, the following vulnerability has been resolved: can: j1939: make j1939_session_activate() fail if device is no longer registered syzbot is …

Impact

In the Linux kernel, the following vulnerability has been resolved: can: j1939: make j1939_session_activate() fail if device is no longer registered syzbot is still reporting unregister_netdevice: waiting for vcan0 to become free. Usage count = 2 even after commit 93a27b5891b8 ("can: j1939: add missing calls in NETDEV_UNREGISTER notification handler") was added. A debug printk() patch found that j1939_session_activate() can succeed even after j1939_cancel_active_session() from j1939_netdev_notify(NETDEV_UNREGISTER) has completed. Since j1939_cancel_active_session() is processed with the session list lock held, checking ndev->reg_state in j1939_session_activate() with the session list lock held can reliably close the race window.

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 5.4.1 before 5.10.248
from 5.11 before 5.15.198
from 5.16 before 6.1.161
from 6.2 before 6.6.121
from 6.7 before 6.12.66
from 6.13 before 6.18.6

Weakness classification

References