net: gro: make sure skb->cb[] initial content has not to be zero
commit29e98242783ed3ba569797846a606ba66f781625
authorEric Dumazet <edumazet@google.com>
Fri, 16 May 2014 18:34:37 +0000 (16 11:34 -0700)
committerDavid S. Miller <davem@davemloft.net>
Fri, 16 May 2014 21:24:54 +0000 (16 17:24 -0400)
tree2d71da0d89ef9f62a4d244fc8d8a92d3f81a802c
parent22fb22eaebf4d16987f3fd9c3484c436ee0badf2
net: gro: make sure skb->cb[] initial content has not to be zero

Starting from linux-3.13, GRO attempts to build full size skbs.

Problem is the commit assumed one particular field in skb->cb[]
was clean, but it is not the case on some stacked devices.

Timo reported a crash in case traffic is decrypted before
reaching a GRE device.

Fix this by initializing NAPI_GRO_CB(skb)->last at the right place,
this also removes one conditional.

Thanks a lot to Timo for providing full reports and bisecting this.

Fixes: 8a29111c7ca6 ("net: gro: allow to build full sized skb")
Bisected-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/dev.c
net/core/skbuff.c