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From: Marc Kleine-Budde <mkl@pengutronix.de>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, linux-can@vger.kernel.org,
	kernel@pengutronix.de, Oleksij Rempel <o.rempel@pengutronix.de>,
	syzbot+afd421337a736d6c1ee6@syzkaller.appspotmail.com,
	syzbot+6d04f6a1b31a0ae12ca9@syzkaller.appspotmail.com
Subject: [PATCH 4/9] can: j1939: socket: rework socket locking for j1939_sk_release() and j1939_sk_sendmsg()
Date: Wed, 13 Nov 2019 10:55:45 +0100	[thread overview]
Message-ID: <20191113095550.26527-5-mkl@pengutronix.de> (raw)
In-Reply-To: <20191113095550.26527-1-mkl@pengutronix.de>

From: Oleksij Rempel <o.rempel@pengutronix.de>

j1939_sk_sendmsg() should be protected by lock_sock() to avoid race with
j1939_sk_bind() and j1939_sk_release().

Reported-by: syzbot+afd421337a736d6c1ee6@syzkaller.appspotmail.com
Reported-by: syzbot+6d04f6a1b31a0ae12ca9@syzkaller.appspotmail.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 net/can/j1939/socket.c | 57 +++++++++++++++++++++++++++++-------------
 1 file changed, 39 insertions(+), 18 deletions(-)

diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index aee94b09ef08..de09b0a65791 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -593,8 +593,8 @@ static int j1939_sk_release(struct socket *sock)
 	if (!sk)
 		return 0;
 
-	jsk = j1939_sk(sk);
 	lock_sock(sk);
+	jsk = j1939_sk(sk);
 
 	if (jsk->state & J1939_SOCK_BOUND) {
 		struct j1939_priv *priv = jsk->priv;
@@ -1092,51 +1092,72 @@ static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
 {
 	struct sock *sk = sock->sk;
 	struct j1939_sock *jsk = j1939_sk(sk);
-	struct j1939_priv *priv = jsk->priv;
+	struct j1939_priv *priv;
 	int ifindex;
 	int ret;
 
+	lock_sock(sock->sk);
 	/* various socket state tests */
-	if (!(jsk->state & J1939_SOCK_BOUND))
-		return -EBADFD;
+	if (!(jsk->state & J1939_SOCK_BOUND)) {
+		ret = -EBADFD;
+		goto sendmsg_done;
+	}
 
+	priv = jsk->priv;
 	ifindex = jsk->ifindex;
 
-	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR)
+	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR) {
 		/* no source address assigned yet */
-		return -EBADFD;
+		ret = -EBADFD;
+		goto sendmsg_done;
+	}
 
 	/* deal with provided destination address info */
 	if (msg->msg_name) {
 		struct sockaddr_can *addr = msg->msg_name;
 
-		if (msg->msg_namelen < J1939_MIN_NAMELEN)
-			return -EINVAL;
+		if (msg->msg_namelen < J1939_MIN_NAMELEN) {
+			ret = -EINVAL;
+			goto sendmsg_done;
+		}
 
-		if (addr->can_family != AF_CAN)
-			return -EINVAL;
+		if (addr->can_family != AF_CAN) {
+			ret = -EINVAL;
+			goto sendmsg_done;
+		}
 
-		if (addr->can_ifindex && addr->can_ifindex != ifindex)
-			return -EBADFD;
+		if (addr->can_ifindex && addr->can_ifindex != ifindex) {
+			ret = -EBADFD;
+			goto sendmsg_done;
+		}
 
 		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
-		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
-			return -EINVAL;
+		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn)) {
+			ret = -EINVAL;
+			goto sendmsg_done;
+		}
 
 		if (!addr->can_addr.j1939.name &&
 		    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
-		    !sock_flag(sk, SOCK_BROADCAST))
+		    !sock_flag(sk, SOCK_BROADCAST)) {
 			/* broadcast, but SO_BROADCAST not set */
-			return -EACCES;
+			ret = -EACCES;
+			goto sendmsg_done;
+		}
 	} else {
 		if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
-		    !sock_flag(sk, SOCK_BROADCAST))
+		    !sock_flag(sk, SOCK_BROADCAST)) {
 			/* broadcast, but SO_BROADCAST not set */
-			return -EACCES;
+			ret = -EACCES;
+			goto sendmsg_done;
+		}
 	}
 
 	ret = j1939_sk_send_loop(priv, sk, msg, size);
 
+sendmsg_done:
+	release_sock(sock->sk);
+
 	return ret;
 }
 
-- 
2.24.0

  parent reply	other threads:[~2019-11-13  9:55 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-13  9:55 pull-request: can 2019-11-13 Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 1/9] can: af_can: export can_sock_destruct() Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 2/9] can: j1939: move j1939_priv_put() into sk_destruct callback Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 3/9] can: j1939: main: j1939_ndev_to_priv(): avoid crash if can_ml_priv is NULL Marc Kleine-Budde
2019-11-13  9:55 ` Marc Kleine-Budde [this message]
2019-11-13  9:55 ` [PATCH 5/9] can: j1939: transport: make sure the aborted session will be deactivated only once Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 6/9] can: j1939: make sure socket is held as long as session exists Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 7/9] can: j1939: transport: j1939_cancel_active_session(): use hrtimer_try_to_cancel() instead of hrtimer_cancel() Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 8/9] can: j1939: j1939_can_recv(): add priv refcounting Marc Kleine-Budde
2019-11-13  9:55 ` [PATCH 9/9] can: j1939: warn if resources are still linked on destroy Marc Kleine-Budde
2019-11-13 19:47 ` pull-request: can 2019-11-13 David Miller

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