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 j1939sessionactivate() fail if device is no longer registered
syzbot is still reporting
unregisternetdevice: waiting for vcan0 to become free. Usage count = 2
even after commit 93a27b5891b8 ("can: j1939: add missing calls in NETDEVUNREGISTER notification handler") was added. A debug printk() patch found that j1939sessionactivate() can succeed even after j1939cancelactivesession() from j1939netdevnotify(NETDEVUNREGISTER) has completed.
Since j1939cancelactivesession() is processed with the session list lock held, checking ndev->regstate in j1939sessionactivate() with the session list lock held can reliably close the race window.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.13-1
Event History
Frequently Asked Questions
What is the severity of CVE-2025-71182?
CVE-2025-71182 is classified as a medium severity vulnerability, affecting certain functions in the Linux kernel.
How do I fix CVE-2025-71182?
To fix CVE-2025-71182, update the Linux Kernel to the latest stable version where this vulnerability has been patched.
What systems are affected by CVE-2025-71182?
CVE-2025-71182 affects systems running vulnerable versions of the Linux kernel that utilize the j1939 CAN protocol.
What could happen if CVE-2025-71182 is exploited?
Exploitation of CVE-2025-71182 could result in denial of service due to failure in session activation for unregistered devices.
Is there a workaround for CVE-2025-71182?
Currently, the recommended solution for CVE-2025-71182 is to promptly apply the kernel update, as no official workaround is available.