From patchwork Thu Jan 6 01:57:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 530413 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31286C433EF for ; Thu, 6 Jan 2022 01:57:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344490AbiAFB5p (ORCPT ); Wed, 5 Jan 2022 20:57:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344496AbiAFB5n (ORCPT ); Wed, 5 Jan 2022 20:57:43 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC561C0611FD; Wed, 5 Jan 2022 17:57:43 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id c2so1278393pfc.1; Wed, 05 Jan 2022 17:57:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=E2ecUMplQVNC6A29lLi9+Ao3qvZ6ZTpS/L9NYSl/HFs=; b=Ylu780cmdIT7XS6RIesWXr4bcMY95FwYaSvL/5mAqAirR+oq31jfbQZYmB6pmXxGjU 0T33yNATsDANC0dG6NJqQDJGBGSeCnUrmyuhKIKmXncxnoTpJ4NeLB1B+b8PmoaefS/d YyZdwaXvTOtYUa8MMWvzR7kafyRRFjSbD7UYt4zodcPjHTKyyIHAipVK3eFbVypzq8Ck keGNO3cYxnahdI6SN/ZMqFxAtYX8o2vUE4hgcKsGPLytu7RiNodaJ70RrItRZlQec3ne qgDpd9W/jcOnWLYpMe5IM/yr1xZNTIYp7hQkiLjj29bfq7eDlIB6hWNU+tehKkw2nQkU ID4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=E2ecUMplQVNC6A29lLi9+Ao3qvZ6ZTpS/L9NYSl/HFs=; b=tu5PWJMxI6/DrMsRniEgh/MQVHCdJJtAGmfN3Jwdw0bDhx/PzvY5dk6eynSIyaXFMu kHad0PoWRzavp7lJnyO+QkuXGOpDIn5OihRh3lv2L5zTxf7UrxzlTY/2idJOgqiCHVN/ XYu6zH/d7QM82WzRcq58S8SRnNapsI9lu4i+kx8BzE+ICvKodcDOm2YtYb2CLOz7aOmq mbUBIeZf75zMSjQYsqaZtQKBxFsiqornacZGpcbOb8HVV6QfaE1L0w//bd4rvMh1yP1F fLmEzgEybtD9LFXfFpQNm7Lcc/Ri/bgomP9P4Mj8Bv4YxIxz3sX5t+mg2t8b3cP9U4gU wthQ== X-Gm-Message-State: AOAM532msL15649M4gFL/yizILjoUJLma7I3ABo8bt0kNXP9GTRv/Osv kP5HxoWNngrK/8wrK8X1YxI= X-Google-Smtp-Source: ABdhPJxipNYYyY4vTr2nrq8dEa3Pg6oFrd6SuL3iGcMvcARJTxZy37OJOGycs6oYxeqT/aLrkCBgQw== X-Received: by 2002:a05:6a00:1485:b0:4bb:317a:a909 with SMTP id v5-20020a056a00148500b004bb317aa909mr58752559pfu.29.1641434263261; Wed, 05 Jan 2022 17:57:43 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id g21sm330910pfc.75.2022.01.05.17.57.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jan 2022 17:57:42 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org, edumazet@google.com Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, shuah@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, Menglong Dong Subject: [PATCH v4 net-next 1/3] net: bpf: handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() Date: Thu, 6 Jan 2022 09:57:19 +0800 Message-Id: <20220106015721.3038819-2-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220106015721.3038819-1-imagedong@tencent.com> References: <20220106015721.3038819-1-imagedong@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Menglong Dong The return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() in __inet_bind() is not handled properly. While the return value is non-zero, it will set inet_saddr and inet_rcv_saddr to 0 and exit: err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; goto out_release_sock; } Let's take UDP for example and see what will happen. For UDP socket, it will be added to 'udp_prot.h.udp_table->hash' and 'udp_prot.h.udp_table->hash2' after the sk->sk_prot->get_port() called success. If 'inet->inet_rcv_saddr' is specified here, then 'sk' will be in the 'hslot2' of 'hash2' that it don't belong to (because inet_saddr is changed to 0), and UDP packet received will not be passed to this sock. If 'inet->inet_rcv_saddr' is not specified here, the sock will work fine, as it can receive packet properly, which is wired, as the 'bind()' is already failed. To undo the get_port() operation, introduce the 'put_port' field for 'struct proto'. For TCP proto, it is inet_put_port(); For UDP proto, it is udp_lib_unhash(); For icmp proto, it is ping_unhash(). Therefore, after sys_bind() fail caused by BPF_CGROUP_RUN_PROG_INET4_POST_BIND(), it will be unbinded, which means that it can try to be binded to another port. Signed-off-by: Menglong Dong --- v3: - NULL check for sk->sk_prot->put_port v2: - introduce 'put_port' field for 'struct proto' --- include/net/sock.h | 1 + net/ipv4/af_inet.c | 2 ++ net/ipv4/ping.c | 1 + net/ipv4/tcp_ipv4.c | 1 + net/ipv4/udp.c | 1 + net/ipv6/af_inet6.c | 2 ++ net/ipv6/ping.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/ipv6/udp.c | 1 + 9 files changed, 11 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index 7b4b4237e6e0..ff9b508d9c5f 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1209,6 +1209,7 @@ struct proto { void (*unhash)(struct sock *sk); void (*rehash)(struct sock *sk); int (*get_port)(struct sock *sk, unsigned short snum); + void (*put_port)(struct sock *sk); #ifdef CONFIG_BPF_SYSCALL int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock, diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index f53184767ee7..9c465bac1eb0 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -531,6 +531,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; + if (sk->sk_prot->put_port) + sk->sk_prot->put_port(sk); goto out_release_sock; } } diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index e540b0dcf085..0e56df3a45e2 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -994,6 +994,7 @@ struct proto ping_prot = { .hash = ping_hash, .unhash = ping_unhash, .get_port = ping_get_port, + .put_port = ping_unhash, .obj_size = sizeof(struct inet_sock), }; EXPORT_SYMBOL(ping_prot); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ac10e4cdd8d0..9861786b8336 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3076,6 +3076,7 @@ struct proto tcp_prot = { .hash = inet_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, + .put_port = inet_put_port, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = tcp_bpf_update_proto, #endif diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 7b18a6f42f18..c2a4411d2b04 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2927,6 +2927,7 @@ struct proto udp_prot = { .unhash = udp_lib_unhash, .rehash = udp_v4_rehash, .get_port = udp_v4_get_port, + .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index d1636425654e..8fe7900f1949 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -413,6 +413,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, if (err) { sk->sk_ipv6only = saved_ipv6only; inet_reset_saddr(sk); + if (sk->sk_prot->put_port) + sk->sk_prot->put_port(sk); goto out; } } diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index 6ac88fe24a8e..9256f6ba87ef 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -177,6 +177,7 @@ struct proto pingv6_prot = { .hash = ping_hash, .unhash = ping_unhash, .get_port = ping_get_port, + .put_port = ping_unhash, .obj_size = sizeof(struct raw6_sock), }; EXPORT_SYMBOL_GPL(pingv6_prot); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 1ac243d18c2b..075ee8a2df3b 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2181,6 +2181,7 @@ struct proto tcpv6_prot = { .hash = inet6_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, + .put_port = inet_put_port, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = tcp_bpf_update_proto, #endif diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 1accc06abc54..90718a924ca8 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1732,6 +1732,7 @@ struct proto udpv6_prot = { .unhash = udp_lib_unhash, .rehash = udp_v6_rehash, .get_port = udp_v6_get_port, + .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif