net: 6lowpan: fix reserved space for single frames

commit ac74f87c789af40936a80131c4759f3e72579c3a upstream.

This patch fixes patch add handling to take care tail and headroom for
single 6lowpan frames. We need to be sure we have a skb with the right
head and tailroom for single frames. This patch do it by using
skb_copy_expand() if head and tailroom is not enough allocated by upper
layer.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195059
Reported-by: David Palma <david.palma@ntnu.no>
Reported-by: Rabi Narayan Sahoo <rabinarayans0828@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexander Aring 2018-07-14 12:52:10 -04:00 committed by Greg Kroah-Hartman
parent ee13f7edca
commit 54c0fa829d

View File

@ -265,9 +265,24 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
/* We must take a copy of the skb before we modify/replace the ipv6
* header as the header could be used elsewhere
*/
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb)
return NET_XMIT_DROP;
if (unlikely(skb_headroom(skb) < ldev->needed_headroom ||
skb_tailroom(skb) < ldev->needed_tailroom)) {
struct sk_buff *nskb;
nskb = skb_copy_expand(skb, ldev->needed_headroom,
ldev->needed_tailroom, GFP_ATOMIC);
if (likely(nskb)) {
consume_skb(skb);
skb = nskb;
} else {
kfree_skb(skb);
return NET_XMIT_DROP;
}
} else {
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb)
return NET_XMIT_DROP;
}
ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
if (ret < 0) {