3.2.100-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
commit 8cb68751c115d176ec851ca56ecfbb411568c9e8 upstream.
If an invalid CAN frame is received, from a driver or from a tun
interface, a Kernel warning is generated.
This patch replaces the WARN_ONCE by a simple pr_warn_once, so that a
kernel, bootet with panic_on_warn, does not panic. A printk seems to be
more appropriate here.
Reported-by: syzbot+4386709c0c1284dca827@xxxxxxxxxxxxxxxxxxxxxxxxx
Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
[bwh: Backported to 3.2:
- Keep using the 'drop' label, as it has another user
- Adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -653,13 +653,13 @@ static int can_rcv(struct sk_buff *skb,
if (!net_eq(dev_net(dev), &init_net))
goto drop;
- if (WARN_ONCE(dev->type != ARPHRD_CAN ||
- skb->len != sizeof(struct can_frame) ||
- cf->can_dlc > 8,
- "PF_CAN: dropped non conform skbuf: "
- "dev type %d, len %d, can_dlc %d\n",
- dev->type, skb->len, cf->can_dlc))
+ if (unlikely(dev->type != ARPHRD_CAN ||
+ skb->len != sizeof(struct can_frame) ||
+ cf->can_dlc > 8)) {
+ pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, can_dlc %d\n",
+ dev->type, skb->len, cf->can_dlc);
goto drop;
+ }
/* update statistics */
can_stats.rx_frames++;