From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH] Fix handling of verdicts after NF_QUEUE Date: Thu, 14 Dec 2017 13:30:08 +0100 Message-ID: <20171214123008.jae4xa4nnpqdeoli@salvia> References: <20171213203337.314-1-dbanerje@akamai.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Debabrata Banerjee , "David S . Miller" , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, stable@vger.kernel.org To: Greg Kroah-Hartman Return-path: Received: from mail.us.es ([193.147.175.20]:46528 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753202AbdLNOgG (ORCPT ); Thu, 14 Dec 2017 09:36:06 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 68321B6B96 for ; Thu, 14 Dec 2017 15:36:04 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id DCB1BA05353 for ; Thu, 14 Dec 2017 15:33:01 +0100 (CET) Content-Disposition: inline In-Reply-To: <20171213203337.314-1-dbanerje@akamai.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi Greg, I'd appreciate if you can take this patch into 4.9-stable. There is no similar patch in tree, so this is not a backport. On Wed, Dec 13, 2017 at 03:33:37PM -0500, Debabrata Banerjee wrote: > A verdict of NF_STOLEN after NF_QUEUE will cause an incorrect return value > and a potential kernel panic via double free of skb's > > This was broken by commit 7034b566a4e7 ("netfilter: fix nf_queue handling") > and subsequently fixed in v4.10 by commit c63cbc460419 ("netfilter: > use switch() to handle verdict cases from nf_hook_slow()"). However that > commit cannot be cleanly cherry-picked to v4.9 > > Signed-off-by: Debabrata Banerjee Acked-by: Pablo Neira Ayuso Thanks a lot! > --- > > This fix is only needed for v4.9 stable since v4.10+ does not have the > issue > --- > net/netfilter/core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/netfilter/core.c b/net/netfilter/core.c > index 004af030ef1a..d869ea50623e 100644 > --- a/net/netfilter/core.c > +++ b/net/netfilter/core.c > @@ -364,6 +364,11 @@ int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state) > ret = nf_queue(skb, state, &entry, verdict); > if (ret == 1 && entry) > goto next_hook; > + } else { > + /* Implicit handling for NF_STOLEN, as well as any other > + * non conventional verdicts. > + */ > + ret = 0; > } > return ret; > } > -- > 2.15.1 >