From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Subject: Re: [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr Date: Thu, 26 Apr 2018 12:51:34 -0300 Message-ID: <20180426155134.GA3814@localhost.localdomain> References: <17bfe46d7b9941f2283043f45ea5644c166c32c3.1524723237.git.lucien.xin@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: network dev , linux-sctp@vger.kernel.org, davem@davemloft.net, Neil Horman , syzkaller@googlegroups.com To: Xin Long Return-path: Received: from mail-qk0-f194.google.com ([209.85.220.194]:45962 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756431AbeDZPvj (ORCPT ); Thu, 26 Apr 2018 11:51:39 -0400 Content-Disposition: inline In-Reply-To: <17bfe46d7b9941f2283043f45ea5644c166c32c3.1524723237.git.lucien.xin@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Apr 26, 2018 at 02:13:57PM +0800, Xin Long wrote: > Since sctp ipv6 socket also supports v4 addrs, it's possible to > compare two v4 addrs in pf v6 .cmp_addr, sctp_inet6_cmp_addr. > > However after Commit 1071ec9d453a ("sctp: do not check port in > sctp_inet6_cmp_addr"), it no longer calls af1->cmp_addr, which > in this case is sctp_v4_cmp_addr, but calls __sctp_v6_cmp_addr > where it handles them as two v6 addrs. It would cause a out of > bounds crash. > > syzbot found this crash when trying to bind two v4 addrs to a > v6 socket. > > This patch fixes it by adding the process for two v4 addrs in > sctp_inet6_cmp_addr. > > Fixes: 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr") > Reported-by: syzbot+cd494c1dd681d4d93ebb@syzkaller.appspotmail.com > Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner > --- > net/sctp/ipv6.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c > index 2e3f7b7..4224711 100644 > --- a/net/sctp/ipv6.c > +++ b/net/sctp/ipv6.c > @@ -895,6 +895,9 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, > if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) > return 1; > > + if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) > + return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; > + > return __sctp_v6_cmp_addr(addr1, addr2); > } > > -- > 2.1.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >