vlan: should take into account needed_headroom
Eric Dumazet [Fri, 18 Mar 2011 00:27:27 +0000 (00:27 +0000)]
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>

net/8021q/vlan_dev.c

index ae610f0..e34ea9e 100644 (file)
@@ -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;