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authorOliver Hartkopp <socketcan@hartkopp.net>2022-05-17 16:56:53 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2022-05-19 22:11:28 +0200
commitb76b163f46b661499921a0049982764a6659bfe7 (patch)
tree7b453791dfaa26c95dd6bf863a3ac249629c7275
parentd7e6f5836038eeac561411ed7a74e2a225a6c138 (diff)
downloadlinux-b76b163f46b661499921a0049982764a6659bfe7.tar.gz
can: isotp: isotp_bind(): do not validate unused address information
With commit 2aa39889c463 ("can: isotp: isotp_bind(): return -EINVAL on
incorrect CAN ID formatting") the bind() syscall returns -EINVAL when
the given CAN ID needed to be sanitized. But in the case of an unconfirmed
broadcast mode the rx CAN ID is not needed and may be uninitialized from
the caller - which is ok.

This patch makes sure the result of an inproper CAN ID format is only
provided when the address information is needed.

Link: https://lore.kernel.org/all/20220517145653.2556-1-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
-rw-r--r--net/can/isotp.c29
1 files changed, 17 insertions, 12 deletions
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 4a4007f10970..43a27d19cdac 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1212,31 +1212,36 @@ 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;
+	canid_t tx_id = addr->can_addr.tp.tx_id;
+	canid_t rx_id = addr->can_addr.tp.rx_id;
 	int err = 0;
 	int notify_enetdown = 0;
 
 	if (len < ISOTP_MIN_NAMELEN)
 		return -EINVAL;
 
-	/* sanitize tx/rx CAN identifiers */
-	tx_id = addr->can_addr.tp.tx_id;
+	/* sanitize tx CAN identifier */
 	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;
-
-	/* give feedback on wrong CAN-ID values */
-	if (tx_id != addr->can_addr.tp.tx_id ||
-	    rx_id != addr->can_addr.tp.rx_id)
+	/* give feedback on wrong CAN-ID value */
+	if (tx_id != addr->can_addr.tp.tx_id)
 		return -EINVAL;
 
+	/* sanitize rx CAN identifier (if needed) */
+	if (isotp_register_rxid(so)) {
+		if (rx_id & CAN_EFF_FLAG)
+			rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+		else
+			rx_id &= CAN_SFF_MASK;
+
+		/* give feedback on wrong CAN-ID value */
+		if (rx_id != addr->can_addr.tp.rx_id)
+			return -EINVAL;
+	}
+
 	if (!addr->can_ifindex)
 		return -ENODEV;