diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-11-09 16:04:46 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-21 10:06:40 +0100 |
| commit | 5c67f9477bb2122a84ad99f6e6d492bebbdf549b (patch) | |
| tree | 67d8eca60ee8823e0e7733e46a5c33f729d81fb0 /net | |
| parent | b67ed647d135d0c0fbb3165d3c7b8c4bd68fe7be (diff) | |
net: __skb_flow_dissect() must cap its return value
[ Upstream commit 34fad54c2537f7c99d07375e50cb30aa3c23bd83 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/flow_dissector.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 4ab6ead3d8ee..9aba9e93c0a2 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -131,7 +131,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector_key_tags *key_tags; struct flow_dissector_key_keyid *key_keyid; u8 ip_proto = 0; - bool ret = false; + bool ret; if (!data) { data = skb->data; @@ -492,12 +492,17 @@ ip_proto_again: out_good: ret = true; -out_bad: + key_control->thoff = (u16)nhoff; +out: key_basic->n_proto = proto; key_basic->ip_proto = ip_proto; - key_control->thoff = (u16)nhoff; return ret; + +out_bad: + ret = false; + key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); + goto out; } EXPORT_SYMBOL(__skb_flow_dissect); |