can: j1939: prevent deadlock by moving j1939_sk_errqueue()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: can: j1939: prevent deadlock by moving j1939_sk_errqueue() This commit addresses a deadlock situation that can occur in certain scenarios, such as when running data TP/ETP transfer and subscribing to the error queue while receiving a net down event. The deadlock involves locks in the following order: 3 j1939_session_list_lock -> active_session_list_lock j1939_session_activate ... j1939_sk_queue_activate_next -> sk_session_queue_lock ... j1939_xtp_rx_eoma_one 2 j1939_sk_queue_drop_all -> sk_session_queue_lock ... j1939_sk_netdev_event_netdown -> j1939_socks_lock j1939_netdev_notify 1 j1939_sk_errqueue -> j1939_socks_lock __j1939_session_cancel -> active_session_list_lock j1939_tp_rxtimer CPU0 CPU1 ---- ---- lock(&priv->active_session_list_lock); lock(&jsk->sk_session_queue_lock); lock(&priv->active_session_list_lock); lock(&priv->j1939_socks_lock); The solution implemented in this commit is to move the j1939_sk_errqueue() call out of the active_session_list_lock context, thus preventing the deadlock situation.

References

• https://git.kernel.org/stable/c/8a581b71cf686b4cd1a85c9c2dfc2fb88382c3b4
• https://git.kernel.org/stable/c/ace6aa2ab5ba5869563ca689bbd912100514ae7b
• https://git.kernel.org/stable/c/f09ce9d765de1f064ce3919f57c6beb061744784
• https://git.kernel.org/stable/c/d1366b283d94ac4537a4b3a1e8668da4df7ce7e9