CVE-2025-71182: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

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

• Linux Linux Kernel: from 5.4.1, before 5.10.248 (fixed in 5.10.248); from 5.11, before 5.15.198 (fixed in 5.15.198); from 5.16, before 6.1.161 (fixed in 6.1.161); from 6.2, before 6.6.121 (fixed in 6.6.121); from 6.7, before 6.12.66 (fixed in 6.12.66); from 6.13, before 6.18.6 (fixed in 6.18.6); …

Published 2026-01-31. Last modified 2026-06-17.