GHSA-266h-p8pw-28f4MediumCVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: can: j1939: make...

Published
January 31, 2026
Last Modified
October 19, 2026

🔗 CVE IDs covered (1)

📋 Description

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.

🔗 References (9)