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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 2BBC5C6377D for ; Thu, 22 Jul 2021 16:42:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 170D66198F for ; Thu, 22 Jul 2021 16:42:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230294AbhGVQCP (ORCPT ); Thu, 22 Jul 2021 12:02:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:37278 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233376AbhGVQAG (ORCPT ); Thu, 22 Jul 2021 12:00:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 57F83610CC; Thu, 22 Jul 2021 16:40:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626972040; bh=XfXf3exzwzQAgYeduepYRS1Ke4hWObA/oZ+ochkmugI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S9dVqSqOLHC5oQYe93UoQexlU68ftQMfLv/IVJ/tsWk/HHb6o35dzIp2VMn2jZsR8 /ucq3hEJifpX+21zKqCG5lEJkIdnOP+EZbbAqpt459G/sTo7D9WfYdD3j2TnVfc5d8 sG+lTHoaYPWsz8iMVG3bcAM7WlmpRCBeEPLkxy5M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Willem de Bruijn , syzbot , "David S. Miller" Subject: [PATCH 5.10 125/125] udp: annotate data races around unix_sk(sk)->gso_size Date: Thu, 22 Jul 2021 18:31:56 +0200 Message-Id: <20210722155628.857112484@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210722155624.672583740@linuxfoundation.org> References: <20210722155624.672583740@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet commit 18a419bad63b7f68a1979e28459782518e7b6bbe upstream. Accesses to unix_sk(sk)->gso_size are lockless. Add READ_ONCE()/WRITE_ONCE() around them. BUG: KCSAN: data-race in udp_lib_setsockopt / udpv6_sendmsg write to 0xffff88812d78f47c of 2 bytes by task 10849 on cpu 1: udp_lib_setsockopt+0x3b3/0x710 net/ipv4/udp.c:2696 udpv6_setsockopt+0x63/0x90 net/ipv6/udp.c:1630 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3265 __sys_setsockopt+0x18f/0x200 net/socket.c:2104 __do_sys_setsockopt net/socket.c:2115 [inline] __se_sys_setsockopt net/socket.c:2112 [inline] __x64_sys_setsockopt+0x62/0x70 net/socket.c:2112 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88812d78f47c of 2 bytes by task 10852 on cpu 0: udpv6_sendmsg+0x161/0x16b0 net/ipv6/udp.c:1299 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2337 ___sys_sendmsg net/socket.c:2391 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2477 __do_sys_sendmmsg net/socket.c:2506 [inline] __se_sys_sendmmsg net/socket.c:2503 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2503 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000 -> 0x0005 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 10852 Comm: syz-executor.0 Not tainted 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/udp.c | 6 +++--- net/ipv6/udp.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1097,7 +1097,7 @@ int udp_sendmsg(struct sock *sk, struct } ipcm_init_sk(&ipc, inet); - ipc.gso_size = up->gso_size; + ipc.gso_size = READ_ONCE(up->gso_size); if (msg->msg_controllen) { err = udp_cmsg_send(sk, msg, &ipc.gso_size); @@ -2655,7 +2655,7 @@ int udp_lib_setsockopt(struct sock *sk, case UDP_SEGMENT: if (val < 0 || val > USHRT_MAX) return -EINVAL; - up->gso_size = val; + WRITE_ONCE(up->gso_size, val); break; case UDP_GRO: @@ -2750,7 +2750,7 @@ int udp_lib_getsockopt(struct sock *sk, break; case UDP_SEGMENT: - val = up->gso_size; + val = READ_ONCE(up->gso_size); break; case UDP_GRO: --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1294,7 +1294,7 @@ int udpv6_sendmsg(struct sock *sk, struc int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); ipcm6_init(&ipc6); - ipc6.gso_size = up->gso_size; + ipc6.gso_size = READ_ONCE(up->gso_size); ipc6.sockc.tsflags = sk->sk_tsflags; ipc6.sockc.mark = sk->sk_mark;