Re: [PATCH] netpoll: Fix skb tail pointer in netpoll_send_udp()

On Tue, 2012-06-12 at 15:15 +0200, Eric Dumazet wrote:

On Tue, 2012-06-12 at 14:22 +0200, Eric Dumazet wrote:

quoted

Hmm, real question is why skb_realloc_headroom() is even necessary...

I suspect we need to reserve more bytes.

	total_len = ip_len + ETH_HLEN + NET_IP_ALIGN + NET_SKB_PAD;

or something like that ?

Which driver triggers the bug ?

In case you wonder why I try so hard to avoid the
skb_realloc_headroom() :

netpoll has complicated^Wspecial^Wnice skb cache, to make sure it can
work even if memory is exhausted.

But if we trigger skb_realloc_headroom() the whole thing is useless. 

Thanks