From patchwork Mon Jul 18 17:26:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12921521 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 834EAC43334 for ; Mon, 18 Jul 2022 17:30:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235789AbiGRRau (ORCPT ); Mon, 18 Jul 2022 13:30:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235378AbiGRRas (ORCPT ); Mon, 18 Jul 2022 13:30:48 -0400 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B236611461 for ; Mon, 18 Jul 2022 10:30:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1658165448; x=1689701448; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8SfzlfUcotWMA3I3Tk+80fhtR80iuIXR7qajXXOmlZU=; b=Z6/0eWNfu9KlgAGFtrDxHkc2r9jnRnP/9ZURWPAA2HDvYgsuXpU6bqkD ucuVJNAvLJ9AqWIFfWzUDGWf9CRwLG1TQZpcSSLJuKtODnjYelSHLv6ho qH/YeaE+XuvOqdj+Zlg1ywSkk4iKtLhQTDZyqd2PDma78U2jRdN6i0VAA w=; X-IronPort-AV: E=Sophos;i="5.92,281,1650931200"; d="scan'208";a="239555659" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-pdx-2c-b09ea7fa.us-west-2.amazon.com) ([10.25.36.210]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP; 18 Jul 2022 17:30:48 +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-2c-b09ea7fa.us-west-2.amazon.com (Postfix) with ESMTPS id 1399D4426E; Mon, 18 Jul 2022 17:30:47 +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 17:30:46 +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 17:30:43 +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 15/15] tcp: Fix data-races around sysctl_tcp_max_reordering. Date: Mon, 18 Jul 2022 10:26:53 -0700 Message-ID: <20220718172653.22111-16-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_max_reordering, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: dca145ffaa8d ("tcp: allow for bigger reordering level") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/tcp_input.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 31a9d2b8ecdc..07dbcbae7782 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1051,7 +1051,7 @@ static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq, tp->undo_marker ? tp->undo_retrans : 0); #endif tp->reordering = min_t(u32, (metric + mss - 1) / mss, - sock_net(sk)->ipv4.sysctl_tcp_max_reordering); + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering)); } /* This exciting event is worth to be remembered. 8) */ @@ -2030,7 +2030,7 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend) return; tp->reordering = min_t(u32, tp->packets_out + addend, - sock_net(sk)->ipv4.sysctl_tcp_max_reordering); + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering)); tp->reord_seen++; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER); }