4.9-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: Oliver Hartkopp socketcan@hartkopp.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/can/af_can.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
--- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -722,13 +722,12 @@ static int can_rcv(struct sk_buff *skb, if (unlikely(!net_eq(dev_net(dev), &init_net))) goto drop;
- 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)) + 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); goto drop; + }
can_receive(skb, dev); return NET_RX_SUCCESS;