From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH v2 net-next 1/2] kcm: Only allow TCP sockets to be attached to a KCM mux Date: Wed, 24 Jan 2018 12:49:16 -0800 Message-ID: <1516826956.3715.29.camel@gmail.com> References: <20180124203541.3172-1-tom@quantonium.net> <20180124203541.3172-2-tom@quantonium.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, rohit@quantonium.net, jchapman@katalix.com, g.nault@alphalink.fr To: Tom Herbert , davem@davemloft.net Return-path: Received: from mail-pf0-f196.google.com ([209.85.192.196]:32920 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932072AbeAXUtR (ORCPT ); Wed, 24 Jan 2018 15:49:17 -0500 Received: by mail-pf0-f196.google.com with SMTP id t5so4063234pfi.0 for ; Wed, 24 Jan 2018 12:49:17 -0800 (PST) In-Reply-To: <20180124203541.3172-2-tom@quantonium.net> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2018-01-24 at 12:35 -0800, Tom Herbert wrote: > TCP sockets for IPv4 and IPv6 that are not listeners or in closed > stated are allowed to be attached to a KCM mux. > > Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") > Reported-by: syzbot+8865eaff7f9acd593945@syzkaller.appspotmail.com > Signed-off-by: Tom Herbert > --- > net/kcm/kcmsock.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c > index d4e98f20fc2a..7632797fb68e 100644 > --- a/net/kcm/kcmsock.c > +++ b/net/kcm/kcmsock.c > @@ -1387,8 +1387,13 @@ static int kcm_attach(struct socket *sock, struct socket *csock, > if (!csk) > return -EINVAL; > > - /* We must prevent loops or risk deadlock ! */ > - if (csk->sk_family == PF_KCM) > + /* Only allow TCP sockets to be attached for now */ > + if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || > + csk->sk_protocol != IPPROTO_TCP) > + return -EOPNOTSUPP; > + > + /* Don't allow listeners or closed sockets */ > + if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) > return -EOPNOTSUPP; > > psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); Reviewed-by: Eric Dumazet