The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8cb68751c115d176ec851ca56ecfbb411568c9e8 Mon Sep 17 00:00:00 2001
From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Date: Tue, 16 Jan 2018 19:30:14 +0100
Subject: [PATCH] can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once
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>
Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 003b2d6d655f..ae835382e678 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -721,20 +721,16 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
{
struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
- if (WARN_ONCE(dev->type != ARPHRD_CAN ||
- skb->len != CAN_MTU ||
- cfd->len > CAN_MAX_DLEN,
- "PF_CAN: dropped non conform CAN skbuf: "
- "dev type %d, len %d, datalen %d\n",
- dev->type, skb->len, cfd->len))
- goto drop;
+ if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU ||
+ cfd->len > CAN_MAX_DLEN)) {
+ pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len);
+ kfree_skb(skb);
+ return NET_RX_DROP;
+ }
can_receive(skb, dev);
return NET_RX_SUCCESS;
-
-drop:
- kfree_skb(skb);
- return NET_RX_DROP;
}
static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,