commit 16fad69cfe4adbbfa813de516757b87bcae36d93
author Eric Dumazet <edumazet@google.com> Thu Mar 14 05:40:32 2013 +0000
committer David S. Miller <davem@davemloft.net> Thu Mar 14 11:49:45 2013 -0400
tree 5b16184db33e16e398fa88ca1dcbb4f054fdaffa
parent b701f16dd490d3f346724050f17d60beda094998

tcp: fix skb_availroom()

Chrome OS team reported a crash on a Pixel ChromeBook in TCP stack :

https://code.google.com/p/chromium/issues/detail?id=182056

commit a21d45726acac (tcp: avoid order-1 allocations on wifi and tx
path) did a poor choice adding an 'avail_size' field to skb, while
what we really needed was a 'reserved_tailroom' one.

It would have avoided commit 22b4a4f22da (tcp: fix retransmit of
partially acked frames) and this commit.

Crash occurs because skb_split() is not aware of the 'avail_size'
management (and should not be aware)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mukesh Agrawal <quiche@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>