pull-request: can 2018-01-18

Hello David,

this is a pull reqeust of two patches for net/master:

The syzkaller project triggered two WARN_ONCE() in the af_can code from
userspace and we decided to replace it by a pr_warn_once().

regards,
Marc

---

The following changes since commit ad9294dbc227cbc8e173b3b963e7dd9af5314f77:

  bpf: fix cls_bpf on filter replace (2018-01-17 17:14:06 -0500)

are available in the Git repository at:

  ssh://git@gitolite.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git tags/linux-can-fixes-for-4.15-20180118

for you to fetch changes up to d4689846881d160a4d12a514e991a740bcb5d65a:

  can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once (2018-01-18 09:32:54 +0100)

----------------------------------------------------------------
linux-can-fixes-for-4.15-20180118

----------------------------------------------------------------
Marc Kleine-Budde (2):
      can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once
      can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once

 net/can/af_can.c | 36 ++++++++++++++----------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

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 <redacted>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 net/can/af_can.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

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,

-- 
2.15.1

If an invalid CANFD 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+e3b775f40babeff6e68b@syzkaller.appspotmail.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <redacted>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 net/can/af_can.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/net/can/af_can.c b/net/can/af_can.c
index ae835382e678..4d7f988a3130 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c

@@ -738,20 +738,16 @@ static int canfd_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 != CANFD_MTU ||
-		      cfd->len > CANFD_MAX_DLEN,
-		      "PF_CAN: dropped non conform CAN FD 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 != CANFD_MTU ||
+		     cfd->len > CANFD_MAX_DLEN)) {
+		pr_warn_once("PF_CAN: dropped non conform CAN FD 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;
 }
 
 /*

-- 
2.15.1

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Thu, 18 Jan 2018 11:15:05 +0100

this is a pull reqeust of two patches for net/master:

The syzkaller project triggered two WARN_ONCE() in the af_can code from
userspace and we decided to replace it by a pr_warn_once().

Pulled, thanks Marc.