Frames can be directly injected to a can driver via the packet
socket. By doing that, it is possible to reach the
net_device_ops::ndo_start_xmit function even if the driver is
configure in listen only mode.
Add a check in can_dropped_invalid_skb() and to discard the skb if
CAN_CTRLMODE_LISTENONLY is set.
Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
---
include/linux/can/dev.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index bbe27e22c7a7..c3ed48e54c29 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -161,6 +161,7 @@ static inline 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 ||
@@ -174,8 +175,13 @@ static inline bool can_dropped_invalid_skb(struct net_device *dev,
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
