summaryrefslogtreecommitdiffstats
path: root/drivers/net/can/dev.c
diff options
context:
space:
mode:
authorMarc Kleine-Budde <mkl@pengutronix.de>2018-10-31 14:15:13 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2018-11-09 17:20:46 +0100
commit7da11ba5c5066dadc2e96835a6233d56d7b7764a (patch)
tree388d431f4cf4512814f35ad4d4b073c4ce7ad46c /drivers/net/can/dev.c
parentcan: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb ... (diff)
downloadlinux-7da11ba5c5066dadc2e96835a6233d56d7b7764a.tar.xz
linux-7da11ba5c5066dadc2e96835a6233d56d7b7764a.zip
can: dev: __can_get_echo_skb(): print error message, if trying to echo non existing skb
Prior to echoing a successfully transmitted CAN frame (by calling can_get_echo_skb()), CAN drivers have to put the CAN frame (by calling can_put_echo_skb() in the transmit function). These put and get function take an index as parameter, which is used to identify the CAN frame. A driver calling can_get_echo_skb() with a index not pointing to a skb is a BUG, so add an appropriate error message. Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/dev.c')
-rw-r--r--drivers/net/can/dev.c27
1 files changed, 14 insertions, 13 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index c05e4d50d43d..3b3f88ffab53 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -480,6 +480,8 @@ EXPORT_SYMBOL_GPL(can_put_echo_skb);
struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
{
struct can_priv *priv = netdev_priv(dev);
+ struct sk_buff *skb = priv->echo_skb[idx];
+ struct canfd_frame *cf;
if (idx >= priv->echo_skb_max) {
netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
@@ -487,21 +489,20 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8
return NULL;
}
- if (priv->echo_skb[idx]) {
- /* Using "struct canfd_frame::len" for the frame
- * length is supported on both CAN and CANFD frames.
- */
- struct sk_buff *skb = priv->echo_skb[idx];
- struct canfd_frame *cf = (struct canfd_frame *)skb->data;
- u8 len = cf->len;
-
- *len_ptr = len;
- priv->echo_skb[idx] = NULL;
-
- return skb;
+ if (!skb) {
+ netdev_err(dev, "%s: BUG! Trying to echo non existing skb: can_priv::echo_skb[%u]\n",
+ __func__, idx);
+ return NULL;
}
- return NULL;
+ /* Using "struct canfd_frame::len" for the frame
+ * length is supported on both CAN and CANFD frames.
+ */
+ cf = (struct canfd_frame *)skb->data;
+ *len_ptr = cf->len;
+ priv->echo_skb[idx] = NULL;
+
+ return skb;
}
/*