From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f174.google.com ([209.85.212.174]:34398 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753651AbbESLbZ (ORCPT ); Tue, 19 May 2015 07:31:25 -0400 Message-ID: <555B1F09.7010300@suse.cz> Date: Tue, 19 May 2015 13:31:21 +0200 From: Jiri Slaby MIME-Version: 1.0 To: Pablo Neira Ayuso , stable@vger.kernel.org CC: netfilter-devel@vger.kernel.org Subject: Re: [PATCH -stable] netfilter: Zero the tuple in nfnl_cthelper_parse_tuple() References: <1431802251-4781-1-git-send-email-pablo@netfilter.org> <1431802251-4781-2-git-send-email-pablo@netfilter.org> In-Reply-To: <1431802251-4781-2-git-send-email-pablo@netfilter.org> Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 05/16/2015, 08:50 PM, Pablo Neira Ayuso wrote: > From: Ian Wilson > > [ upstream commit 78146572b9cd20452da47951812f35b1ad4906be ] > > nfnl_cthelper_parse_tuple() is called from nfnl_cthelper_new(), > nfnl_cthelper_get() and nfnl_cthelper_del(). In each case they pass > a pointer to an nf_conntrack_tuple data structure local variable: > > struct nf_conntrack_tuple tuple; > ... > ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); > > The problem is that this local variable is not initialized, and > nfnl_cthelper_parse_tuple() only initializes two fields: src.l3num and > dst.protonum. This leaves all other fields with undefined values > based on whatever is on the stack: > > tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); > tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); > > The symptom observed was that when the rpc and tns helpers were added > then traffic to port 1536 was being sent to user-space. > > Cc: # 3.10.x > Cc: # 3.12.x Applied only this one to 3.12 (others are not marked as such). Thanks. > Cc: # 3.14.x > Cc: # 3.18.x > Cc: # 3.19.x > Signed-off-by: Ian Wilson > Signed-off-by: Pablo Neira Ayuso > --- > net/netfilter/nfnetlink_cthelper.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c > index a5599fc..54330fb 100644 > --- a/net/netfilter/nfnetlink_cthelper.c > +++ b/net/netfilter/nfnetlink_cthelper.c > @@ -77,6 +77,9 @@ nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, > if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) > return -EINVAL; > > + /* Not all fields are initialized so first zero the tuple */ > + memset(tuple, 0, sizeof(struct nf_conntrack_tuple)); > + > tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); > tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); > > -- js suse labs