leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

net: __skb_flow_dissect() must cap its return value

Browse Source 
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: a6e544b0a8 ("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>
This commit is contained in:
Eric Dumazet 2016-11-09 16:04:46 -08:00 committed by David S. Miller
parent 79774d6bfa
commit 34fad54c25
1 changed files with 8 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
net/core/flow_dissector.c
View File

@ -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);