tree cca25bcae0cc6172a616335041c1e54a33db451c
parent 93b174ad71b08e504c2cf6e8a58ecce778b77a40
author Eric Dumazet <edumazet@google.com> 1354802099 +0000
committer David S. Miller <davem@davemloft.net> 1354909169 -0500

net: gro: fix possible panic in skb_gro_receive()

commit 2e71a6f8084e (net: gro: selective flush of packets) added
a bug for skbs using frag_list. This part of the GRO stack is rarely
used, as it needs skb not using a page fragment for their skb->head.

Most drivers do use a page fragment, but some of them use GFP_KERNEL
allocations for the initial fill of their RX ring buffer.

napi_gro_flush() overwrite skb->prev that was used for these skb to
point to the last skb in frag_list.

Fix this using a separate field in struct napi_gro_cb to point to the
last fragment.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>