From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> Frames can be directly injected to a can driver via the packet socket. By doing so, it is possible to reach the net_device_ops::ndo_start_xmit function even if the driver is configured in listen only mode. Add a check in can_dropped_invalid_skb() to discard the skb if CAN_CTRLMODE_LISTENONLY is set. Link: https://lore.kernel.org/all/20220610143009.323579-8-mailhol.vincent@xxxxxxxxxx Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> Acked-by: Max Staudt <max@xxxxxxxxx> Tested-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/dev/skb.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index dc9da76c0470..8bb62dd864c8 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -5,6 +5,7 @@ */ #include <linux/can/dev.h> +#include <linux/can/netlink.h> #include <linux/module.h> #define MOD_DESC "CAN device driver interface" @@ -293,6 +294,7 @@ static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb) bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb) { const struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + struct can_priv *priv = netdev_priv(dev); if (skb->protocol == htons(ETH_P_CAN)) { if (unlikely(skb->len != CAN_MTU || @@ -306,8 +308,13 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb) goto inval_skb; } - if (!can_skb_headroom_valid(dev, skb)) + if (!can_skb_headroom_valid(dev, skb)) { + goto inval_skb; + } else if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) { + netdev_info_once(dev, + "interface in listen only mode, dropping skb\n"); goto inval_skb; + } return false; -- 2.35.1
