Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752192AbbBQPzf (ORCPT ); Tue, 17 Feb 2015 10:55:35 -0500 Received: from mail-qc0-f181.google.com ([209.85.216.181]:63973 "EHLO mail-qc0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751638AbbBQPze (ORCPT ); Tue, 17 Feb 2015 10:55:34 -0500 Message-ID: <1424188529.4942.80.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: [PATCH] ipv4: ip_check_defrag should correctly check return value of skb_copy_bits From: Eric Dumazet To: Alexander Drozdov , Johannes Berg Cc: "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 17 Feb 2015 07:55:29 -0800 In-Reply-To: <1424169226-30112-1-git-send-email-al.drozdov@gmail.com> References: <1424169226-30112-1-git-send-email-al.drozdov@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1296 Lines: 34 On Tue, 2015-02-17 at 13:33 +0300, Alexander Drozdov wrote: > skb_copy_bits() returns zero on success and negative value on error, > so it is needed to invert the condition in ip_check_defrag(). > > Fixes: 1bf3751ec90c ("ipv4: ip_check_defrag must not modify skb before unsharing") > Signed-off-by: Alexander Drozdov > --- > net/ipv4/ip_fragment.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c > index e5b6d0d..2c8d98e 100644 > --- a/net/ipv4/ip_fragment.c > +++ b/net/ipv4/ip_fragment.c > @@ -664,7 +664,7 @@ struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) > if (skb->protocol != htons(ETH_P_IP)) > return skb; > > - if (!skb_copy_bits(skb, 0, &iph, sizeof(iph))) > + if (skb_copy_bits(skb, 0, &iph, sizeof(iph)) < 0) > return skb; > > if (iph.ihl < 5 || iph.version != 4) Thanks, I wonder how this was not found/fixed earlier. Acked-by: Eric Dumazet Cc: Johannes Berg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/