path: root/drivers/net/xen-netback/netback.c
diff options
authorMaxim Mikityanskiy <maximmi@mellanox.com>2019-02-21 12:39:57 +0000
committerDavid S. Miller <davem@davemloft.net>2019-02-22 12:55:31 -0800
commitd2aa125d629080c4f3e31f23b7f612ef6b8492ac (patch)
tree85cd897e246a879c33393582949935cb26ad1784 /drivers/net/xen-netback/netback.c
parentMerge tag 'mac80211-next-for-davem-2019-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next (diff)
net: Don't set transport offset to invalid value
If the socket was created with socket(AF_PACKET, SOCK_RAW, 0), skb->protocol will be unset, __skb_flow_dissect() will fail, and skb_probe_transport_header() will fall back to the offset_hint, making the resulting skb_transport_offset incorrect. If, however, there is no transport header in the packet, transport_header shouldn't be set to an arbitrary value. Fix it by leaving the transport offset unset if it couldn't be found, to be explicit rather than to fill it with some wrong value. It changes the behavior, but if some code relied on the old behavior, it would be broken anyway, as the old one is incorrect. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 80aae3a32c2a..c801a832851c 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1169,15 +1169,24 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
- skb_probe_transport_header(skb, 0);
+ skb_probe_transport_header(skb);
/* If the packet is GSO then we will have just set up the
* transport header offset in checksum_setup so it's now
* straightforward to calculate gso_segs.
if (skb_is_gso(skb)) {
- int mss = skb_shinfo(skb)->gso_size;
- int hdrlen = skb_transport_header(skb) -
+ int mss, hdrlen;
+ /* GSO implies having the L4 header. */
+ WARN_ON_ONCE(!skb_transport_header_was_set(skb));
+ if (unlikely(!skb_transport_header_was_set(skb))) {
+ kfree_skb(skb);
+ continue;
+ }
+ mss = skb_shinfo(skb)->gso_size;
+ hdrlen = skb_transport_header(skb) -
skb_mac_header(skb) +