CVE-2025-71182 — can: j1939: make j1939_session_activate() fail if device is no longer registered
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 …
Published: 2026-01-31 · CVSS: Unscored
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7