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. Reported-by:<syzbot+ee1cd780f69483a8616b@syzkaller.appspotmail.com> Fixes: 5b9272e9 ("can: j1939: extend UAPI to notify about RX status") Co-developed-by:
Hillf Danton <hdanton@sina.com> Signed-off-by:
Hillf Danton <hdanton@sina.com> Signed-off-by:
Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/all/20230324130141.2132787-1-o.rempel@pengutronix.de Cc: stable@vger.kernel.org Signed-off-by:
Marc Kleine-Budde <mkl@pengutronix.de>
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