From patchwork Mon Nov 25 23:37:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Maciej_=C5=BBenczykowski?= X-Patchwork-Id: 1200663 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="FKWCnt0n"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47MNkP0LF2z9s3Z for ; Tue, 26 Nov 2019 10:37:48 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726876AbfKYXhN (ORCPT ); Mon, 25 Nov 2019 18:37:13 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:36792 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbfKYXhM (ORCPT ); Mon, 25 Nov 2019 18:37:12 -0500 Received: by mail-pg1-f194.google.com with SMTP id k13so8007831pgh.3 for ; Mon, 25 Nov 2019 15:37:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CpO0K+NtuEPdqlzSdniAA05bXddH4rJuXAK0KAuUx7Y=; b=FKWCnt0nMfhXU3wqSdiDjxFFDvbDjV/n1XbWYabJjLTfmuFcGO5t2RW5YOtz4Kk3vq bI8V4457w6DGSEmiIOlmXw+nYDSqQn5xFP72iC3Y2ovF6NDmdGEKyDfdlJne3H1bpv4I ZS2jtOrGR8IOWrLvR68HjXEF297t9xT6IOpITqWEDfaGpGzuyB+ozIapeHDPiVIU7qgX XnvL/mRUJiFWDGwyCzBduxOY8+d/GWj/Gfr6G8IJS9X7dD+CQn9+u+SnQzwdebAskjhF ETxJ09xlk3zDZ24GkTYm6ZuHxPeR4qC3RvRNBNtUiiY9zatGfaDmlu8w8mMQU7ICxuAq RttA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CpO0K+NtuEPdqlzSdniAA05bXddH4rJuXAK0KAuUx7Y=; b=AM8QYSCLnR+4+SaamSnwywL/4rrgJi8JpDyhRBRePkXjba0ZWA/uSXx9c5glh5vENb n9uvzTf7NZ999eeCCRqjr/MRSYwhIHhNkJ3pEH1HgbT+sUJ0NqB0moHvXUZsn/w1/Qyg LrGYK9b3HlVCF4H6iEd1dxUADkUEz6ZQHbX23PK+BE2BD3SmuLqQsYuslQnbINGIo1wx /TXCw/qrnWsPz5Ij8dzgs/nOOWXB9Fd5zFUbX6uzlBbvvTAEWJ+QMdZ8XrvT1kGjrtMf h7r6ZrP8QcwJwzOKfHdXWp5UJnC2WRW4vc/t+Dz//uNNk8GldODz1RziYAiFRjvMR9/1 +b5g== X-Gm-Message-State: APjAAAXZ1YlQDyBeqMtS8ch2Rn6+VwLga3Shmr95C89lfJs9kjOCfhuD mPlc66zzkaLOYvLPKGiasNoDp6hF X-Google-Smtp-Source: APXvYqxg4c2EOytq5oLPwwhiNGi2Mq9AOKMF3sQgy5S+1t3KWspng7b3TgCEnbvCO+d9uix1pra/eA== X-Received: by 2002:a65:4c4c:: with SMTP id l12mr34147169pgr.377.1574725031885; Mon, 25 Nov 2019 15:37:11 -0800 (PST) Received: from athina.mtv.corp.google.com ([2620:15c:211:0:c786:d9fd:ab91:6283]) by smtp.gmail.com with ESMTPSA id u20sm9687169pgf.29.2019.11.25.15.37.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Nov 2019 15:37:11 -0800 (PST) From: =?utf-8?q?Maciej_=C5=BBenczykowski?= To: =?utf-8?q?Maciej_=C5=BBenczykowski?= , "David S . Miller" Cc: netdev@vger.kernel.org, Eric Dumazet Subject: [PATCH v2] net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port) Date: Mon, 25 Nov 2019 15:37:04 -0800 Message-Id: <20191125233704.186202-1-zenczykowski@gmail.com> X-Mailer: git-send-email 2.24.0.432.g9d3f5f5b63-goog In-Reply-To: References: MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Maciej Żenczykowski Note that the sysctl write accessor functions guarantee that: net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0] invariant is maintained, and as such the max() in selinux hooks is actually spurious. ie. even though if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) { per logic is the same as if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) { it is actually functionally equivalent to: if (snum < low || snum > high) { which is equivalent to: if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) { even though the first clause is spurious. But we want to hold on to it in case we ever want to change what what inet_port_requires_bind_service() means (for example by changing it from a, by default, [0..1024) range to some sort of set). Test: builds, git 'grep inet_prot_sock' finds no other references Cc: Eric Dumazet Signed-off-by: Maciej Żenczykowski --- include/net/ip.h | 8 ++++---- net/ipv4/af_inet.c | 2 +- net/ipv6/af_inet6.c | 2 +- net/netfilter/ipvs/ip_vs_ctl.c | 2 +- net/sctp/socket.c | 4 ++-- security/selinux/hooks.c | 4 ++-- 6 files changed, 11 insertions(+), 11 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index cebf3e10def1..5a61bd948b18 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -351,9 +351,9 @@ static inline bool sysctl_dev_name_is_allowed(const char *name) return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; } -static inline int inet_prot_sock(struct net *net) +static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) { - return net->ipv4.sysctl_ip_prot_sock; + return port < net->ipv4.sysctl_ip_prot_sock; } #else @@ -362,9 +362,9 @@ static inline bool inet_is_local_reserved_port(struct net *net, int port) return false; } -static inline int inet_prot_sock(struct net *net) +static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) { - return PROT_SOCK; + return port < PROT_SOCK; } #endif diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 53de8e00990e..2fe295432c24 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -495,7 +495,7 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, snum = ntohs(addr->sin_port); err = -EACCES; - if (snum && snum < inet_prot_sock(net) && + if (snum && inet_port_requires_bind_service(net, snum) && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) goto out; diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index ef37e0574f54..60e2ff91a5b3 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -292,7 +292,7 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, return -EINVAL; snum = ntohs(addr->sin6_port); - if (snum && snum < inet_prot_sock(net) && + if (snum && inet_port_requires_bind_service(net, snum) && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) return -EACCES; diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 3be7398901e0..8d14a1acbc37 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -423,7 +423,7 @@ ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u32 fwmark, __u16 protocol if (!svc && protocol == IPPROTO_TCP && atomic_read(&ipvs->ftpsvc_counter) && - (vport == FTPDATA || ntohs(vport) >= inet_prot_sock(ipvs->net))) { + (vport == FTPDATA || !inet_port_requires_bind_service(ipvs->net, ntohs(vport)))) { /* * Check if ftp service entry exists, the packet * might belong to FTP data connections. diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 83e4ca1fabda..8797a38baf00 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -384,7 +384,7 @@ static int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len) } } - if (snum && snum < inet_prot_sock(net) && + if (snum && inet_port_requires_bind_service(net, snum) && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) return -EACCES; @@ -1061,7 +1061,7 @@ static int sctp_connect_new_asoc(struct sctp_endpoint *ep, if (sctp_autobind(sk)) return -EAGAIN; } else { - if (ep->base.bind_addr.port < inet_prot_sock(net) && + if (inet_port_requires_bind_service(net, ep->base.bind_addr.port) && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) return -EACCES; } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9625b99e677f..753b327f4806 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4623,8 +4623,8 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in inet_get_local_port_range(sock_net(sk), &low, &high); - if (snum < max(inet_prot_sock(sock_net(sk)), low) || - snum > high) { + if (inet_port_requires_bind_service(sock_net(sk), snum) || + snum < low || snum > high) { err = sel_netport_sid(sk->sk_protocol, snum, &sid); if (err)