4.9-stable review patch. If anyone has any objections, please let me know.
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From: Alexander Aring aring@mojatatu.com
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
--- net/ieee802154/6lowpan/tx.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
--- a/net/ieee802154/6lowpan/tx.c +++ b/net/ieee802154/6lowpan/tx.c @@ -266,9 +266,24 @@ netdev_tx_t lowpan_xmit(struct sk_buff * /* 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) {