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| author | Oliver Hartkopp <oliver@hartkopp.net> | 2009-08-13 22:54:25 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-08-14 16:36:57 -0700 |
| commit | 1758c0947605211ef953cc91d6bbdf847a21b822 (patch) | |
| tree | 695e60450ec85f7e48b00949c29324c89eca7f20 /net | |
| parent | 49d4b8ba97034469b941d00d5ca1e3b897394e35 (diff) | |
| download | linux-stable-1758c0947605211ef953cc91d6bbdf847a21b822.tar.gz linux-stable-1758c0947605211ef953cc91d6bbdf847a21b822.tar.bz2 linux-stable-1758c0947605211ef953cc91d6bbdf847a21b822.zip | |
can: Use WARN_ONCE() instead of BUG_ON() for sanity check in receive path
To ensure a proper handling of CAN frames transported in skbuffs some checks
need to be performed at receive time.
As stated by Michael Olbrich and Luotao Fu BUG_ON() might be to restrictive.
This is right as we can just drop the non conform skbuff and the Kernel can
continue working.
This patch replaces the BUG_ON() with a WARN_ONCE() so that the system remains
healthy but we made the problem visible (once).
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Urs Thuermann <urs@isnogud.escape.de>
CC: Michael Olbrich <m.olbrich@pengutronix.de>
CC: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/can/af_can.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c index e733725b11d4..f9c027be78b2 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -651,12 +651,16 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, struct can_frame *cf = (struct can_frame *)skb->data; int matches; - if (dev->type != ARPHRD_CAN || !net_eq(dev_net(dev), &init_net)) { - kfree_skb(skb); - return 0; - } + if (!net_eq(dev_net(dev), &init_net)) + goto drop; - BUG_ON(skb->len != sizeof(struct can_frame) || cf->can_dlc > 8); + if (WARN_ONCE(dev->type != ARPHRD_CAN || + skb->len != sizeof(struct can_frame) || + cf->can_dlc > 8, + "PF_CAN: dropped non conform skbuf: " + "dev type %d, len %d, can_dlc %d\n", + dev->type, skb->len, cf->can_dlc)) + goto drop; /* update statistics */ can_stats.rx_frames++; @@ -683,6 +687,10 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, } return 0; + +drop: + kfree_skb(skb); + return 0; } /* |