vlan: should take into account needed_headroom

Commit c95b819ad7 (gre: Use needed_headroom)
made gre use needed_headroom instead of hard_header_len

This uncover a bug in vlan code.

We should make sure vlan devices take into account their
real_dev->needed_headroom or we risk a crash in ipgre_header(), because
we dont have enough room to push IP header in skb.

Reported-by: Diddi Oscarsson <diddi@diddi.se>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index ae610f046de5..e34ea9e5e28b 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -720,6 +720,7 @@ static int vlan_dev_init(struct net_device *dev)
         dev->fcoe_ddp_xid = real_dev->fcoe_ddp_xid;
 #endif
 
+        dev->needed_headroom = real_dev->needed_headroom;
         if (real_dev->features & NETIF_F_HW_VLAN_TX) {
                 dev->header_ops      = real_dev->header_ops;
                 dev->hard_header_len = real_dev->hard_header_len;