net: __skb_flow_dissect() must cap its return value
authorEric Dumazet <edumazet@google.com>
Thu, 10 Nov 2016 00:04:46 +0000 (16:04 -0800)
committerDavid S. Miller <davem@davemloft.net>
Sun, 13 Nov 2016 04:41:53 +0000 (23:41 -0500)
commit34fad54c2537f7c99d07375e50cb30aa3c23bd83
treea63fc00dc48c8673830e2930aed819ccfb2f9632
parent79774d6bfacb40699ecd5a343e5d4ac5a9cdd173
net: __skb_flow_dissect() must cap its return value

After Tom patch, thoff field could point past the end of the buffer,
this could fool some callers.

If an skb was provided, skb->len should be the upper limit.
If not, hlen is supposed to be the upper limit.

Fixes: a6e544b0a88b ("flow_dissector: Jump to exit code in __skb_flow_dissect")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Yibin Yang <yibyang@cisco.com
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/flow_dissector.c