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authorOleksij Rempel <o.rempel@pengutronix.de>2023-03-24 16:01:41 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2023-03-27 12:03:22 +0300
commitd1366b283d94ac4537a4b3a1e8668da4df7ce7e9 (patch)
tree2952998ad89fcf39b6c80e78a0c77e2f7cc97c25 /net/can
parent45977e58ce65ed0459edc9a0466d9dfea09463f5 (diff)
downloadlinux-d1366b283d94ac4537a4b3a1e8668da4df7ce7e9.tar.xz
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: 5b9272e93f2e ("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>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/j1939/transport.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index fce9b9ebf13f..fb92c3609e17 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1124,8 +1124,6 @@ static void __j1939_session_cancel(struct j1939_session *session,
if (session->sk)
j1939_sk_send_loop_abort(session->sk, session->err);
- else
- j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
}
static void j1939_session_cancel(struct j1939_session *session,
@@ -1140,6 +1138,9 @@ static void j1939_session_cancel(struct j1939_session *session,
}
j1939_session_list_unlock(session->priv);
+
+ if (!session->sk)
+ j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
}
static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
@@ -1253,6 +1254,9 @@ static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
__j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
}
j1939_session_list_unlock(session->priv);
+
+ if (!session->sk)
+ j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
}
j1939_session_put(session);