CVE-2025-39925

Description

In the Linux kernel, the following vulnerability has been resolved:can: j1939: implement NETDEV_UNREGISTER notification handlersyzbot is reporting unregister_netdevice: waiting for vcan0 to become free. Usage count = 2problem, for j1939 protocol did not have NETDEV_UNREGISTER notificationhandler for undoing changes made by j1939_sk_bind().Commit 25fe97cb7620 (can: j1939: move j1939_priv_put() into sk_destructcallback) expects that a call to j1939_priv_put() can be unconditionallydelayed until j1939_sk_sock_destruct() is called. But we need to callj1939_priv_put() against an extra ref held by j1939_sk_bind() call(as a part of undoing changes made by j1939_sk_bind()) as soon asNETDEV_UNREGISTER notification fires (i.e. before j1939_sk_sock_destruct()is called via j1939_sk_release()). Otherwise, the extra ref on structj1939_priv held by j1939_sk_bind() call prevents struct net_device fromdropping the usage count to 1; making it impossible forunregister_netdevice() to continue.[mkl: remove space in front of label]

Risk Information

Base Score

5.5

MODERATE

Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Score

Exploitation Probability

0.018

Associated Vulnerability

No records found

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234