diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-11-09 16:04:46 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-12 23:41:53 -0500 |
| commit | 34fad54c2537f7c99d07375e50cb30aa3c23bd83 (patch) | |
| tree | a63fc00dc48c8673830e2930aed819ccfb2f9632 /net/core | |
| parent | 79774d6bfacb40699ecd5a343e5d4ac5a9cdd173 (diff) | |
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>
Diffstat (limited to 'net/core')
| -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 ab193e5def07..69e4463a4b1b 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -122,7 +122,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector_key_keyid *key_keyid; bool skip_vlan = false; u8 ip_proto = 0; - bool ret = false; + bool ret; if (!data) { data = skb->data; @@ -549,12 +549,17 @@ 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); |