flow dissector: check if arp_eth is null rather than arp

arp is being checked instead of arp_eth to see if the call to
__skb_header_pointer failed. Fix this by checking arp_eth is
null instead of arp.   Also fix to use length hlen rather than
hlen - sizeof(_arp); thanks to Eric Dumazet for spotting
this latter issue.

CoverityScan CID#1396428 ("Logically dead code") on 2nd
arp comparison (which should be arp_eth instead).

Fixes: commit 55733350e5 ("flow disector: ARP support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Colin Ian King 2017-01-13 18:48:20 +00:00 committed by David S. Miller
parent e89df81317
commit 57b68ec2a7

View File

@ -407,9 +407,9 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
sizeof(_arp_eth), data,
hlen - sizeof(_arp),
hlen,
&_arp_eth);
if (!arp)
if (!arp_eth)
goto out_bad;
if (dissector_uses_key(flow_dissector,