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Message-Id: <20230327124807.1157134-2-mkl@pengutronix.de>
Date: Mon, 27 Mar 2023 14:48:06 +0200
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, kuba@...nel.org, linux-can@...r.kernel.org,
kernel@...gutronix.de, Oleksij Rempel <o.rempel@...gutronix.de>,
syzbot+ee1cd780f69483a8616b@...kaller.appspotmail.com,
Hillf Danton <hdanton@...a.com>, stable@...r.kernel.org,
Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [PATCH net 1/2] can: j1939: prevent deadlock by moving j1939_sk_errqueue()
From: Oleksij Rempel <o.rempel@...gutronix.de>
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@...kaller.appspotmail.com
Fixes: 5b9272e93f2e ("can: j1939: extend UAPI to notify about RX status")
Co-developed-by: Hillf Danton <hdanton@...a.com>
Signed-off-by: Hillf Danton <hdanton@...a.com>
Signed-off-by: Oleksij Rempel <o.rempel@...gutronix.de>
Link: https://lore.kernel.org/all/20230324130141.2132787-1-o.rempel@pengutronix.de
Cc: stable@...r.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
---
net/can/j1939/transport.c | 8 ++++++--
1 file 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);
base-commit: 45977e58ce65ed0459edc9a0466d9dfea09463f5
--
2.39.2
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