From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Herbert Subject: [PATCH v2 net-next 1/2] kcm: Only allow TCP sockets to be attached to a KCM mux Date: Wed, 24 Jan 2018 12:35:40 -0800 Message-ID: <20180124203541.3172-2-tom@quantonium.net> References: <20180124203541.3172-1-tom@quantonium.net> Cc: netdev@vger.kernel.org, rohit@quantonium.net, jchapman@katalix.com, g.nault@alphalink.fr, Tom Herbert To: davem@davemloft.net Return-path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:40537 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932072AbeAXUi3 (ORCPT ); Wed, 24 Jan 2018 15:38:29 -0500 Received: by mail-pg0-f67.google.com with SMTP id g16so3523880pgn.7 for ; Wed, 24 Jan 2018 12:38:29 -0800 (PST) In-Reply-To: <20180124203541.3172-1-tom@quantonium.net> Sender: netdev-owner@vger.kernel.org List-ID: 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); -- 2.11.0