From patchwork Mon Jul 18 17:26:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12921516 X-Patchwork-Delegate: kuba@kernel.org 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 9867DC43334 for ; Mon, 18 Jul 2022 17:29:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233951AbiGRR3y (ORCPT ); Mon, 18 Jul 2022 13:29:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235743AbiGRR3t (ORCPT ); Mon, 18 Jul 2022 13:29:49 -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 835EA9FCC for ; Mon, 18 Jul 2022 10:29:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1658165388; x=1689701388; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6WqUCNxeFg+iZ/LBApc6SHLeg5ooLFCJIcKQTO1v08o=; b=nV0e1BRrKi0oEPn7Sf1j+75B2oIJO8hGVDFD0IK2+wPyER+dJuu0Poit nYjDKb8iujZ815uQD0WfMMAuzULItV8UbNKyilO0fK1tbbY6l35cYazHW hGZJYIPHIAcsiQ9f34ywU8uBOKm8127SCaFMP1h2NH23gx05G+rM+v6va w=; X-IronPort-AV: E=Sophos;i="5.92,281,1650931200"; d="scan'208";a="1035321695" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2a-11a39b7d.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-9103.sea19.amazon.com with ESMTP; 18 Jul 2022 17:29:48 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan3.pdx.amazon.com [10.236.137.198]) by email-inbound-relay-pdx-2a-11a39b7d.us-west-2.amazon.com (Postfix) with ESMTPS id 944CB43EF4; Mon, 18 Jul 2022 17:29:47 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Mon, 18 Jul 2022 17:29:46 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.159) 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 15.2.1118.9; Mon, 18 Jul 2022 17:29:44 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern CC: Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH v1 net 11/15] tcp: Fix a data-race around sysctl_tcp_retrans_collapse. Date: Mon, 18 Jul 2022 10:26:49 -0700 Message-ID: <20220718172653.22111-12-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220718172653.22111-1-kuniyu@amazon.com> References: <20220718172653.22111-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.159] X-ClientProxiedBy: EX13D04UWA004.ant.amazon.com (10.43.160.234) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While reading sysctl_tcp_retrans_collapse, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 51120407c570..c38e07b50639 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3105,7 +3105,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, struct sk_buff *skb = to, *tmp; bool first = true; - if (!sock_net(sk)->ipv4.sysctl_tcp_retrans_collapse) + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retrans_collapse)) return; if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) return;