Merge tag 'linux-can-next-for-5.18-20220316' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2022-03-16

the first 3 patches are by Oliver Hartkopp target the CAN ISOTP
protocol and fix a problem found by syzbot in isotp_bind(), return
-EADDRNOTAVAIL in unbound sockets in isotp_recvmsg() and add support
for MSG_TRUNC to isotp_recvmsg().

Amit Kumar Mahapatra converts the xilinx,can device tree bindings to
yaml.

The last patch is by Julia Lawall and fixes typos in the ucan driver.

* tag 'linux-can-next-for-5.18-20220316' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next:
  can: ucan: fix typos in comments
  dt-bindings: can: xilinx_can: Convert Xilinx CAN binding to YAML
  can: isotp: support MSG_TRUNC flag when reading from socket
  can: isotp: return -EADDRNOTAVAIL when reading from unbound socket
  can: isotp: sanitize CAN ID checks in isotp_bind()
====================

Link: https://lore.kernel.org/r/20220316204710.716341-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 40 insertions, 32 deletions

diff --git a/net/can/isotp.c b/net/can/isotp.c
index d4c0b4704987..f6f8ba1f816d 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1046,26 +1046,29 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 {
 	struct sock *sk = sock->sk;
 	struct sk_buff *skb;
-	int err = 0;
-	int noblock;
+	struct isotp_sock *so = isotp_sk(sk);
+	int noblock = flags & MSG_DONTWAIT;
+	int ret = 0;
 
-	noblock = flags & MSG_DONTWAIT;
-	flags &= ~MSG_DONTWAIT;
+	if (flags & ~(MSG_DONTWAIT | MSG_TRUNC))
+		return -EINVAL;
 
-	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!so->bound)
+		return -EADDRNOTAVAIL;
+
+	flags &= ~MSG_DONTWAIT;
+	skb = skb_recv_datagram(sk, flags, noblock, &ret);
 	if (!skb)
-		return err;
+		return ret;
 
 	if (size < skb->len)
 		msg->msg_flags |= MSG_TRUNC;
 	else
 		size = skb->len;
 
-	err = memcpy_to_msg(msg, skb->data, size);
-	if (err < 0) {
-		skb_free_datagram(sk, skb);
-		return err;
-	}
+	ret = memcpy_to_msg(msg, skb->data, size);
+	if (ret < 0)
+		goto out_err;
 
 	sock_recv_timestamp(msg, sk, skb);
 
@@ -1075,9 +1078,13 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 	}
 
+	/* set length of return value */
+	ret = (flags & MSG_TRUNC) ? skb->len : size;
+
+out_err:
 	skb_free_datagram(sk, skb);
 
-	return size;
+	return ret;
 }
 
 static int isotp_release(struct socket *sock)
@@ -1148,6 +1155,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	struct net *net = sock_net(sk);
 	int ifindex;
 	struct net_device *dev;
+	canid_t tx_id, rx_id;
 	int err = 0;
 	int notify_enetdown = 0;
 	int do_rx_reg = 1;
@@ -1155,8 +1163,18 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	if (len < ISOTP_MIN_NAMELEN)
 		return -EINVAL;
 
-	if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
-		return -EADDRNOTAVAIL;
+	/* sanitize tx/rx CAN identifiers */
+	tx_id = addr->can_addr.tp.tx_id;
+	if (tx_id & CAN_EFF_FLAG)
+		tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+	else
+		tx_id &= CAN_SFF_MASK;
+
+	rx_id = addr->can_addr.tp.rx_id;
+	if (rx_id & CAN_EFF_FLAG)
+		rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+	else
+		rx_id &= CAN_SFF_MASK;
 
 	if (!addr->can_ifindex)
 		return -ENODEV;
@@ -1168,21 +1186,13 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 		do_rx_reg = 0;
 
 	/* do not validate rx address for functional addressing */
-	if (do_rx_reg) {
-		if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) {
-			err = -EADDRNOTAVAIL;
-			goto out;
-		}
-
-		if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
-			err = -EADDRNOTAVAIL;
-			goto out;
-		}
+	if (do_rx_reg && rx_id == tx_id) {
+		err = -EADDRNOTAVAIL;
+		goto out;
 	}
 
 	if (so->bound && addr->can_ifindex == so->ifindex &&
-	    addr->can_addr.tp.rx_id == so->rxid &&
-	    addr->can_addr.tp.tx_id == so->txid)
+	    rx_id == so->rxid && tx_id == so->txid)
 		goto out;
 
 	dev = dev_get_by_index(net, addr->can_ifindex);
@@ -1206,16 +1216,14 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	ifindex = dev->ifindex;
 
 	if (do_rx_reg) {
-		can_rx_register(net, dev, addr->can_addr.tp.rx_id,
-				SINGLE_MASK(addr->can_addr.tp.rx_id),
+		can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
 				isotp_rcv, sk, "isotp", sk);
 
 		/* no consecutive frame echo skb in flight */
 		so->cfecho = 0;
 
 		/* register for echo skb's */
-		can_rx_register(net, dev, addr->can_addr.tp.tx_id,
-				SINGLE_MASK(addr->can_addr.tp.tx_id),
+		can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
 				isotp_rcv_echo, sk, "isotpe", sk);
 	}
 
@@ -1239,8 +1247,8 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 
 	/* switch to new settings */
 	so->ifindex = ifindex;
-	so->rxid = addr->can_addr.tp.rx_id;
-	so->txid = addr->can_addr.tp.tx_id;
+	so->rxid = rx_id;
+	so->txid = tx_id;
 	so->bound = 1;
 
 out: