From: Marc Kleine-Budde <mkl@pengutronix.de>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org,
kernel@pengutronix.de, Oleksij Rempel <o.rempel@pengutronix.de>,
linux-stable <stable@vger.kernel.org>,
Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com,
Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [net 4/5] can: j1939: j1939_sk_init(): set SOCK_RCU_FREE to call sk_destruct() after RCU is done
Date: Sun, 20 Jun 2021 00:01:14 +0200 [thread overview]
Message-ID: <20210619220115.2830761-5-mkl@pengutronix.de> (raw)
In-Reply-To: <20210619220115.2830761-1-mkl@pengutronix.de>
From: Oleksij Rempel <o.rempel@pengutronix.de>
Set SOCK_RCU_FREE to let RCU to call sk_destruct() on completion.
Without this patch, we will run in to j1939_can_recv() after priv was
freed by j1939_sk_release()->j1939_sk_sock_destruct()
Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback")
Link: https://lore.kernel.org/r/20210617130623.12705-1-o.rempel@pengutronix.de
Cc: linux-stable <stable@vger.kernel.org>
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Reported-by: syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/j1939/main.c | 4 ++++
net/can/j1939/socket.c | 3 +++
2 files changed, 7 insertions(+)
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index da3a7a7bcff2..08c8606cfd9c 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -193,6 +193,10 @@ static void j1939_can_rx_unregister(struct j1939_priv *priv)
can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
j1939_can_recv, priv);
+ /* The last reference of priv is dropped by the RCU deferred
+ * j1939_sk_sock_destruct() of the last socket, so we can
+ * safely drop this reference here.
+ */
j1939_priv_put(priv);
}
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index 56aa66147d5a..fce8bc8afeb7 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -398,6 +398,9 @@ static int j1939_sk_init(struct sock *sk)
atomic_set(&jsk->skb_pending, 0);
spin_lock_init(&jsk->sk_session_queue_lock);
INIT_LIST_HEAD(&jsk->sk_session_queue);
+
+ /* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */
+ sock_set_flag(sk, SOCK_RCU_FREE);
sk->sk_destruct = j1939_sk_sock_destruct;
sk->sk_protocol = CAN_J1939;
--
2.30.2
next prev parent reply other threads:[~2021-06-19 22:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-19 22:01 pull-request: can 2021-06-19 Marc Kleine-Budde
2021-06-19 22:01 ` [net 1/5] can: bcm: delay release of struct bcm_op after synchronize_rcu() Marc Kleine-Budde
2021-06-19 22:01 ` [net 2/5] can: gw: synchronize rcu operations before removing gw job entry Marc Kleine-Budde
2021-06-19 22:01 ` [net 3/5] can: isotp: isotp_release(): omit unintended hrtimer restart on socket release Marc Kleine-Budde
2021-06-19 22:01 ` Marc Kleine-Budde [this message]
2021-06-19 22:01 ` [net 5/5] net: can: ems_usb: fix use-after-free in ems_usb_disconnect() Marc Kleine-Budde
2021-06-21 19:50 ` pull-request: can 2021-06-19 patchwork-bot+netdevbpf
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