From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: [PATCH net v3] sctp: asconf's process should verify address parameter is in the beginning Date: Wed, 26 Aug 2015 16:42:21 -0400 Message-ID: <55DE24AD.5090507@redhat.com> References: Reply-To: vyasevic@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: mleitner@redhat.com, davem@davemloft.net To: Xin Long , network dev Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57849 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752722AbbHZUmX (ORCPT ); Wed, 26 Aug 2015 16:42:23 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 08/26/2015 04:35 PM, Xin Long wrote: > in sctp_process_asconf(), we get address parameter from the beginning of > the addip params. but we never check if it's really there. if the addr > param is not there, it still can pass sctp_verify_asconf(), then to be > handled by sctp_process_asconf(), it will not be safe. > > so add a code in sctp_verify_asconf() to check the address parameter is in > the beginning, or return false to send abort. > > v2->v3: > * put the check in the loop, add the check for multiple address parameters. Please split the multiple address detection from first address detection. They are 2 different bugs and each one deserves a separate commit and changelog. Thanks -vlad > v1->v2: > * put the check behind the params' length verify. > > Signed-off-by: Xin Long > Signed-off-by: Vlad Yasevich > --- > net/sctp/sm_make_chunk.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c > index 06320c8..4068fe1 100644 > --- a/net/sctp/sm_make_chunk.c > +++ b/net/sctp/sm_make_chunk.c > @@ -3130,14 +3130,24 @@ bool sctp_verify_asconf(const struct sctp_association *asoc, > case SCTP_PARAM_ERR_CAUSE: > break; > case SCTP_PARAM_IPV4_ADDRESS: > + if (addr_param_seen) { > + /* peer placed multiple address parameters into > + * the same asconf. reject it. > + */ > + return false; > + } > if (length != sizeof(sctp_ipv4addr_param_t)) > return false; > - addr_param_seen = true; > + if (param.v == addip->addip_hdr.params) > + addr_param_seen = true; > break; > case SCTP_PARAM_IPV6_ADDRESS: > + if (addr_param_seen) > + return false; > if (length != sizeof(sctp_ipv6addr_param_t)) > return false; > - addr_param_seen = true; > + if (param.v == addip->addip_hdr.params) > + addr_param_seen = true; > break; > case SCTP_PARAM_ADD_IP: > case SCTP_PARAM_DEL_IP: >