From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin King Subject: [PATCH][V2] flow dissector: check if arp_eth is null rather than arp Date: Fri, 13 Jan 2017 18:48:20 +0000 Message-ID: <20170113184820.823-1-colin.king@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Cc: linux-kernel@vger.kernel.org To: "David S . Miller" , Alexander Duyck , Jiri Pirko , Tom Herbert , Eric Dumazet , Hadar Hen Zion , Simon Horman , Gao Feng , Amir Vadai , netdev@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Colin Ian King 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 55733350e5e8b70c5 ("flow disector: ARP support") Signed-off-by: Colin Ian King --- net/core/flow_dissector.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index e3dffc7..c35aae1 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -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, -- 2.10.2