4.14-stable review patch. If anyone has any objections, please let me know.
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From: Marc Kleine-Budde mkl@pengutronix.de
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@syzkaller.appspotmail.com Suggested-by: Dmitry Vyukov dvyukov@google.com Acked-by: Oliver Hartkopp socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/can/af_can.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)
--- 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 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,