[PATCH v1] can: j1939: j1939_sk_init(): set SOCK_RCU_FREE to call sk_destruct() after RCU is done
From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2021-06-17 13:06:39
Also in:
linux-can, lkml
Subsystem:
can network layer, can-j1939 network layer, the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, Robin van der Gracht, Oleksij Rempel, Linus Torvalds
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()
Reported-by: Thadeu Lima de Souza Cascardo <redacted>
Reported-by: syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com
Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
net/can/j1939/socket.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index 56aa66147d5a..c7c1b4d4c0fb 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); + + sock_set_flag(sk, SOCK_RCU_FREE); + /* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */ sk->sk_destruct = j1939_sk_sock_destruct; sk->sk_protocol = CAN_J1939;
--
2.29.2