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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E694C433EF for ; Fri, 25 Feb 2022 15:29:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242091AbiBYP3w (ORCPT ); Fri, 25 Feb 2022 10:29:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242101AbiBYP3v (ORCPT ); Fri, 25 Feb 2022 10:29:51 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F3442177D7 for ; Fri, 25 Feb 2022 07:29:19 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 08F27617E5 for ; Fri, 25 Feb 2022 15:29:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C127C340E7; Fri, 25 Feb 2022 15:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645802958; bh=O6kRX+DYW38hxtgnkth8h2JXQ/VCcx5VAszkPQD81jU=; h=Subject:To:Cc:From:Date:From; b=Fys74fI8yJ/HODEyGEnxJcGq/AH5xh3D9Yr9mU+R8boapUCYhh741BPsZPz8qclFG Vw1Z52FLy3+jAH5cNmGYZ3vrtvx2noPp5vZRv/Zpz6Q0QfjV/KkRCz640g8BqlXW+Z 4GiecBuYkZeZGqtHSj6tu7TvHRWb3vsiChZeWQNU= Subject: FAILED: patch "[PATCH] net-timestamp: convert sk->sk_tskey to atomic_t" failed to apply to 5.4-stable tree To: edumazet@google.com, davem@davemloft.net, syzkaller@googlegroups.com, willemb@google.com Cc: From: Date: Fri, 25 Feb 2022 16:29:08 +0100 Message-ID: <16458029488110@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a1cdec57e03a1352e92fbbe7974039dda4efcec0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 17 Feb 2022 09:05:02 -0800 Subject: [PATCH] net-timestamp: convert sk->sk_tskey to atomic_t UDP sendmsg() can be lockless, this is causing all kinds of data races. This patch converts sk->sk_tskey to remove one of these races. BUG: KCSAN: data-race in __ip_append_data / __ip_append_data read to 0xffff8881035d4b6c of 4 bytes by task 8877 on cpu 1: __ip_append_data+0x1c1/0x1de0 net/ipv4/ip_output.c:994 ip_make_skb+0x13f/0x2d0 net/ipv4/ip_output.c:1636 udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff8881035d4b6c of 4 bytes by task 8880 on cpu 0: __ip_append_data+0x1d8/0x1de0 net/ipv4/ip_output.c:994 ip_make_skb+0x13f/0x2d0 net/ipv4/ip_output.c:1636 udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000054d -> 0x0000054e Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8880 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 09c2d251b707 ("net-timestamp: add key to disambiguate concurrent datagrams") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Reported-by: syzbot Signed-off-by: David S. Miller diff --git a/include/net/sock.h b/include/net/sock.h index ff9b508d9c5f..50aecd28b355 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -507,7 +507,7 @@ struct sock { #endif u16 sk_tsflags; u8 sk_shutdown; - u32 sk_tskey; + atomic_t sk_tskey; atomic_t sk_zckey; u8 sk_clockid; @@ -2667,7 +2667,7 @@ static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags, __sock_tx_timestamp(tsflags, tx_flags); if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey && tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) - *tskey = sk->sk_tskey++; + *tskey = atomic_inc_return(&sk->sk_tskey) - 1; } if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS))) *tx_flags |= SKBTX_WIFI_STATUS; diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index a271688780a2..307ee1174a6e 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -2006,7 +2006,7 @@ struct j1939_session *j1939_tp_send(struct j1939_priv *priv, /* set the end-packet for broadcast */ session->pkt.last = session->pkt.total; - skcb->tskey = session->sk->sk_tskey++; + skcb->tskey = atomic_inc_return(&session->sk->sk_tskey) - 1; session->tskey = skcb->tskey; return session; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9d0388bed0c1..6a15ce3eb1d3 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4730,7 +4730,7 @@ static void __skb_complete_tx_timestamp(struct sk_buff *skb, if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) { serr->ee.ee_data = skb_shinfo(skb)->tskey; if (sk_is_tcp(sk)) - serr->ee.ee_data -= sk->sk_tskey; + serr->ee.ee_data -= atomic_read(&sk->sk_tskey); } err = sock_queue_err_skb(sk, skb); diff --git a/net/core/sock.c b/net/core/sock.c index 4ff806d71921..6eb174805bf0 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -879,9 +879,9 @@ int sock_set_timestamping(struct sock *sk, int optname, if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) return -EINVAL; - sk->sk_tskey = tcp_sk(sk)->snd_una; + atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una); } else { - sk->sk_tskey = 0; + atomic_set(&sk->sk_tskey, 0); } } diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 139cec29ed06..7911916a480b 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -991,7 +991,7 @@ static int __ip_append_data(struct sock *sk, if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) - tskey = sk->sk_tskey++; + tskey = atomic_inc_return(&sk->sk_tskey) - 1; hh_len = LL_RESERVED_SPACE(rt->dst.dev); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 2995f8d89e7e..304a295de84f 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1465,7 +1465,7 @@ static int __ip6_append_data(struct sock *sk, if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) - tskey = sk->sk_tskey++; + tskey = atomic_inc_return(&sk->sk_tskey) - 1; hh_len = LL_RESERVED_SPACE(rt->dst.dev);