In Linux 4.12 commit 8e8cda6d737d356054c ("can: initial support for network namespaces") removed a namespace check which affected this patch:
upstream commit 8cb68751c115d176ec851ca56ecfbb411568c9e8
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@syzkaller.appspotmail.com Suggested-by: Dmitry Vyukov dvyukov@google.com Acked-by: Oliver Hartkopp socketcan@hartkopp.net Cc: linux-stable stable@vger.kernel.org [pre 4.12] Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Oliver Hartkopp socketcan@hartkopp.net --- net/can/af_can.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/net/can/af_can.c b/net/can/af_can.c index 928f58064098..924ad0513af9 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -722,13 +722,12 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, 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;