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 E70F4C00144 for ; Mon, 1 Aug 2022 11:48:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231519AbiHALsT (ORCPT ); Mon, 1 Aug 2022 07:48:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231482AbiHALsF (ORCPT ); Mon, 1 Aug 2022 07:48:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1D50357ED; Mon, 1 Aug 2022 04:48:04 -0700 (PDT) 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 9155A612C5; Mon, 1 Aug 2022 11:48:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EDC0C433D7; Mon, 1 Aug 2022 11:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354484; bh=/qYEJzRwOPh3lmTo2H4V8MfPr1kkl0t/ufrJ74RZtfk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kwiiy6FpoLhBLrv+i933LY/5ILEyM3VV0fv6xu4I/7OYjB+awTj9b+ZmNqwfOCUq2 /XZa+g1pgV0Kg6d+6GTQX5O1ZYUXgK+QVig6zMhqehFDuwhYK1pHNG/h58v4Gd4pb4 5y/l0SR98/nYDPWp7hoiydC/CVuYElksdZWkyhjI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" Subject: [PATCH 5.4 12/34] tcp: Fix a data-race around sysctl_tcp_limit_output_bytes. Date: Mon, 1 Aug 2022 13:46:52 +0200 Message-Id: <20220801114128.501168275@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114128.025615151@linuxfoundation.org> References: <20220801114128.025615151@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima commit 9fb90193fbd66b4c5409ef729fd081861f8b6351 upstream. While reading sysctl_tcp_limit_output_bytes, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 46d3ceabd8d9 ("tcp: TCP Small Queues") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2276,7 +2276,7 @@ static bool tcp_small_queue_check(struct sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift)); if (sk->sk_pacing_status == SK_PACING_NONE) limit = min_t(unsigned long, limit, - sock_net(sk)->ipv4.sysctl_tcp_limit_output_bytes); + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_limit_output_bytes)); limit <<= factor; if (static_branch_unlikely(&tcp_tx_delay_enabled) &&