From patchwork Wed Jul 6 23:39:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12908913 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 969A2CCA482 for ; Wed, 6 Jul 2022 23:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234762AbiGFXmz (ORCPT ); Wed, 6 Jul 2022 19:42:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234958AbiGFXml (ORCPT ); Wed, 6 Jul 2022 19:42:41 -0400 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2A392CE05; Wed, 6 Jul 2022 16:42:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657150960; x=1688686960; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=WrRefD5BgkzIzv5gXe6/gL75Imx09IKo5AaSxIEliV4=; b=PwlIbTlzCepYu3l/LGa8ey873Y0dgDJ9XSwX+E/g5m8PEL7tYKrMqOdX ooAIFfBiOMmyHClQocRBvqcQElxK9Lz+kI7CiJqP4lX4dMjGDs3EJf9h1 K8jWWxIXjE8bmKMI4GcMyFLGuKmnbvVq2GQ6QslmI87lpS0cAyGPHnzQ5 8=; X-IronPort-AV: E=Sophos;i="5.92,251,1650931200"; d="scan'208";a="105640207" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-iad-1a-c92fe759.us-east-1.amazon.com) ([10.25.36.214]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP; 06 Jul 2022 23:42:23 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1a-c92fe759.us-east-1.amazon.com (Postfix) with ESMTPS id 9B400C0846; Wed, 6 Jul 2022 23:42:20 +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 15.0.1497.36; Wed, 6 Jul 2022 23:42:19 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.106) 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; Wed, 6 Jul 2022 23:42:16 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Luis Chamberlain , Kees Cook , Iurii Zaikin CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v2 net 07/12] tcp: Fix a data-race around sysctl_tcp_max_orphans. Date: Wed, 6 Jul 2022 16:39:58 -0700 Message-ID: <20220706234003.66760-8-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220706234003.66760-1-kuniyu@amazon.com> References: <20220706234003.66760-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.160.106] X-ClientProxiedBy: EX13D36UWB001.ant.amazon.com (10.43.161.84) 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_orphans, it can be changed concurrently. So, we need to add READ_ONCE() to avoid a data-race. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- net/ipv4/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 028513d3e2a2..2222dfdde316 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2715,7 +2715,8 @@ static void tcp_orphan_update(struct timer_list *unused) static bool tcp_too_many_orphans(int shift) { - return READ_ONCE(tcp_orphan_cache) << shift > sysctl_tcp_max_orphans; + return READ_ONCE(tcp_orphan_cache) << shift > + READ_ONCE(sysctl_tcp_max_orphans); } bool tcp_check_oom(struct sock *sk, int shift)