From patchwork Wed Jan 5 13:18:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 530264 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 CA505C433F5 for ; Wed, 5 Jan 2022 13:21:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240200AbiAENU6 (ORCPT ); Wed, 5 Jan 2022 08:20:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240097AbiAENUx (ORCPT ); Wed, 5 Jan 2022 08:20:53 -0500 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87680C061761; Wed, 5 Jan 2022 05:20:52 -0800 (PST) Received: by mail-pj1-x1044.google.com with SMTP id jw3so33853387pjb.4; Wed, 05 Jan 2022 05:20:52 -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:mime-version :content-transfer-encoding; bh=7Kq4c8juE/76qRYRMXs2lRmxlZAz+IUatIP4ilaj/U8=; b=FhEushG+NbzS34uQM16aiw4qNHSQsgJc+WpJovQnanI/MvACDqdr+BWjtvvppqjqe+ kwgtqtF9BBpcNWbqqM9v5kYt0j17yWeG0FApC/jDwTiN9sMwAHSM4y0tRRPOQy37r1G+ GgcmwRmPU8QXWVkAN7Zcfc5yIfoeKEqh8L3DUe5GtjAHp3q1g0H0mR2XokX5sM7HAcnZ p+iAXqhEehKEZiOfS3bPDkyPNjur9bq+5rGs2Cqqbu/b2llDvxnU0FaqruCs4SzQolOM CIB+raF4YvzVlW75MoTQWKbZB735wHcUpoazJKJQUM2dVvbASvkw286JOZ57LA1Mxfg1 eMQw== 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:mime-version :content-transfer-encoding; bh=7Kq4c8juE/76qRYRMXs2lRmxlZAz+IUatIP4ilaj/U8=; b=JuPUI/0pMI29JI9NFdpn92fWPdcd5Gygxw3aN4k437rhjcZPAmx1+fCe0Oaze1JVaK R3K2Uxd3Jf0zR05Dk2kPjsl8K1jgP9wT/Ag+lCOTMZqqy1fTPDLSsUXMQb4Q0oT2HiuL UTh+uznesCV7DKJ8+zO6qJKxRNF+sRg1bPVTxYpJVwwkkTlkcZk+qsLE9eILelq+hhk4 067kuUPhToLcqtqq1lqTWEvS38Y8ZpW45DRfyg6FeMwyShsHsLLdkmJjA1i/KpDXQKDL nrA0ffTJ10Mipx7y71Gnl41hUI3Ecd9K+tHfYOWIPFhnFDiAnqtFqW8B43DeMQOI6gC3 frFA== X-Gm-Message-State: AOAM533fEZrEp5cPETgZdy2HEjHzIyWpNDj4HpOUi1N9K1uV+99MOhn2 evEhrdmd1RGZpzoBnSgg++o= X-Google-Smtp-Source: ABdhPJwU8Ch1WwInyAZUimpDw3jwMVHk8mF/C0YBiVKcpXMPw5GRtTJnQofqROE+SKZktisEtbHajg== X-Received: by 2002:a17:90a:fa6:: with SMTP id 35mr3984087pjz.165.1641388852020; Wed, 05 Jan 2022 05:20:52 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id q17sm16227771pfj.119.2022.01.05.05.20.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jan 2022 05:20:51 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org, daniel@iogearbox.net Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, edumazet@google.com, shuah@kernel.org, ast@kernel.org, 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 v3 net-next 0/2] net: bpf: handle return value of post_bind{4,6} and add selftests for it Date: Wed, 5 Jan 2022 21:18:47 +0800 Message-Id: <20220105131849.2559506-1-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 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: 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. The second patch is the selftests for this modification. Changes since v2: - NULL check for sk->sk_prot->put_port Changes since v1: - introduce 'put_port' field for 'struct proto' - add selftests for it Menglong Dong (2): net: bpf: handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() bpf: selftests: add bind retry for post_bind{4, 6} 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 + tools/testing/selftests/bpf/test_sock.c | 166 +++++++++++++++++++++--- 10 files changed, 157 insertions(+), 20 deletions(-)