From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C42A7C5DF60 for ; Fri, 8 Nov 2019 19:08:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9512721D7F for ; Fri, 8 Nov 2019 19:08:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573240089; bh=z62dywJAMWmfYIJF3fIu6pSyjyH7/Oe9eeZghcAxork=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LkVHAmxRFJgjDy2EBGTYEohMDHh5Pw0MfvgNYnw5HVCt71Wuwm8aZKz63u+S/l6iM wGmRVD2M1hF5npZsPfTZ8F/sJJetBUeJ3DHo/Mt/Pe5jBRwMx7kKvpSD9C/hpeCFG2 BCciSevsjj1yYlgcuxfXGRYeTxwOnB/eUpukTVBk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387775AbfKHTII (ORCPT ); Fri, 8 Nov 2019 14:08:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:38978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391551AbfKHTIF (ORCPT ); Fri, 8 Nov 2019 14:08:05 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 905A021D7F; Fri, 8 Nov 2019 19:08:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573240084; bh=z62dywJAMWmfYIJF3fIu6pSyjyH7/Oe9eeZghcAxork=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kkuTcr/bqv8MvQCkwfkZGg3PhwTPUMB9wecpY6CyuR5L1V/i9qxAW2DljwfGw7h+G tlEje1jnola01sMCHCG3WELBoZ0QKz3E+i77w6MIWmq6lsT+Y+8v0KPZzfgZmUQHD/ r+4XbVctNkhH3j2Wn3Jmp/yOs+HBHtqCWdpcId/Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , "David S. Miller" Subject: [PATCH 5.3 084/140] net: annotate accesses to sk->sk_incoming_cpu Date: Fri, 8 Nov 2019 19:50:12 +0100 Message-Id: <20191108174910.393815813@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191108174900.189064908@linuxfoundation.org> References: <20191108174900.189064908@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit 7170a977743b72cf3eb46ef6ef89885dc7ad3621 ] This socket field can be read and written by concurrent cpus. Use READ_ONCE() and WRITE_ONCE() annotations to document this, and avoid some compiler 'optimizations'. KCSAN reported : BUG: KCSAN: data-race in tcp_v4_rcv / tcp_v4_rcv write to 0xffff88812220763c of 4 bytes by interrupt on cpu 0: sk_incoming_cpu_update include/net/sock.h:953 [inline] tcp_v4_rcv+0x1b3c/0x1bb0 net/ipv4/tcp_ipv4.c:1934 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124 process_backlog+0x1d3/0x420 net/core/dev.c:5955 napi_poll net/core/dev.c:6392 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6460 __do_softirq+0x115/0x33f kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189 read to 0xffff88812220763c of 4 bytes by interrupt on cpu 1: sk_incoming_cpu_update include/net/sock.h:952 [inline] tcp_v4_rcv+0x181a/0x1bb0 net/ipv4/tcp_ipv4.c:1934 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124 process_backlog+0x1d3/0x420 net/core/dev.c:5955 napi_poll net/core/dev.c:6392 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6460 __do_softirq+0x115/0x33f kernel/softirq.c:292 run_ksoftirqd+0x46/0x60 kernel/softirq.c:603 smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/sock.h | 4 ++-- net/core/sock.c | 4 ++-- net/ipv4/inet_hashtables.c | 2 +- net/ipv4/udp.c | 2 +- net/ipv6/inet6_hashtables.c | 2 +- net/ipv6/udp.c | 2 +- 6 files changed, 8 insertions(+), 8 deletions(-) --- a/include/net/sock.h +++ b/include/net/sock.h @@ -949,8 +949,8 @@ static inline void sk_incoming_cpu_updat { int cpu = raw_smp_processor_id(); - if (unlikely(sk->sk_incoming_cpu != cpu)) - sk->sk_incoming_cpu = cpu; + if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu)) + WRITE_ONCE(sk->sk_incoming_cpu, cpu); } static inline void sock_rps_record_flow_hash(__u32 hash) --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1125,7 +1125,7 @@ set_rcvbuf: break; } case SO_INCOMING_CPU: - sk->sk_incoming_cpu = val; + WRITE_ONCE(sk->sk_incoming_cpu, val); break; case SO_CNX_ADVICE: @@ -1474,7 +1474,7 @@ int sock_getsockopt(struct socket *sock, break; case SO_INCOMING_CPU: - v.val = sk->sk_incoming_cpu; + v.val = READ_ONCE(sk->sk_incoming_cpu); break; case SO_MEMINFO: --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -240,7 +240,7 @@ static inline int compute_score(struct s return -1; score = sk->sk_family == PF_INET ? 2 : 1; - if (sk->sk_incoming_cpu == raw_smp_processor_id()) + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) score++; } return score; --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -388,7 +388,7 @@ static int compute_score(struct sock *sk return -1; score += 4; - if (sk->sk_incoming_cpu == raw_smp_processor_id()) + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) score++; return score; } --- a/net/ipv6/inet6_hashtables.c +++ b/net/ipv6/inet6_hashtables.c @@ -105,7 +105,7 @@ static inline int compute_score(struct s return -1; score = 1; - if (sk->sk_incoming_cpu == raw_smp_processor_id()) + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) score++; } return score; --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -135,7 +135,7 @@ static int compute_score(struct sock *sk return -1; score++; - if (sk->sk_incoming_cpu == raw_smp_processor_id()) + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) score++; return score;