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 059ACC32772 for ; Tue, 23 Aug 2022 19:17:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233582AbiHWTRG (ORCPT ); Tue, 23 Aug 2022 15:17:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234121AbiHWTQi (ORCPT ); Tue, 23 Aug 2022 15:16:38 -0400 Received: from smtp-fw-9103.amazon.com (smtp-fw-9103.amazon.com [207.171.188.200]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BECB780E8E for ; Tue, 23 Aug 2022 10:53:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1661277237; x=1692813237; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=xPluUW9NioNNMw+y8Fb93UL6h1Y47k0AhjYaFy7MaI8=; b=SbtGBJxN9lz6I8Q5KKkObdeT3GZGweWPZZvK2AHO8kvxkcinJX5Z0I5a 03H7BlXtXv93k5KHj9mXBemy8JBZ4tEIVe3mUfGlt7IhPm4Lp29g3h+rZ gDqT13KVJk6dShlkc37E2TOsQgaunTKWnWN3I2pRNJiWL7gqzLAPvf0NT Q=; X-IronPort-AV: E=Sophos;i="5.93,258,1654560000"; d="scan'208";a="1047381719" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2a-e6c05252.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-9103.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Aug 2022 17:51:01 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-pdx-2a-e6c05252.us-west-2.amazon.com (Postfix) with ESMTPS id 5177F44A7F; Tue, 23 Aug 2022 17:51:01 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Tue, 23 Aug 2022 17:51:00 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.160) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Tue, 23 Aug 2022 17:50:58 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Hans Westgaard Ry Subject: [PATCH v4 net 11/17] net: Fix data-races around sysctl_max_skb_frags. Date: Tue, 23 Aug 2022 10:46:54 -0700 Message-ID: <20220823174700.88411-12-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220823174700.88411-1-kuniyu@amazon.com> References: <20220823174700.88411-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.160.160] X-ClientProxiedBy: EX13D07UWA003.ant.amazon.com (10.43.160.35) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While reading sysctl_max_skb_frags, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags") Signed-off-by: Kuniyuki Iwashima --- CC: Hans Westgaard Ry --- net/ipv4/tcp.c | 4 ++-- net/mptcp/protocol.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bbe218753662..e5011c136fdb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1000,7 +1000,7 @@ static struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags, i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, page, offset); - if (!can_coalesce && i >= sysctl_max_skb_frags) { + if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) { tcp_mark_push(tp, skb); goto new_segment; } @@ -1354,7 +1354,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { - if (i >= sysctl_max_skb_frags) { + if (i >= READ_ONCE(sysctl_max_skb_frags)) { tcp_mark_push(tp, skb); goto new_segment; } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index da4257504fad..d398f3810662 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1263,7 +1263,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, dfrag->page, offset); - if (!can_coalesce && i >= sysctl_max_skb_frags) { + if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) { tcp_mark_push(tcp_sk(ssk), skb); goto alloc_skb; } -- 2.30.2