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 A6375C6FA82 for ; Fri, 2 Sep 2022 12:21:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236028AbiIBMVa (ORCPT ); Fri, 2 Sep 2022 08:21:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235804AbiIBMVP (ORCPT ); Fri, 2 Sep 2022 08:21:15 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F4079CCD7; Fri, 2 Sep 2022 05:21:03 -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 ams.source.kernel.org (Postfix) with ESMTPS id 1141FB82A8F; Fri, 2 Sep 2022 12:21:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6011AC433D6; Fri, 2 Sep 2022 12:21:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662121260; bh=ShxWmdastEh/OaWYqrIvumXK97FZMf4Sx12fYRQGky4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DvZjSK4uDTr31vh4G/mSF+xkzfo48jCTC62zxcKCoZnfIIuqxzwZ1hpm/IPUuRQxE ovvnax6NWD18wCvvb6J/Q7V5LmPP2KJgxYBR024oOZP4tK1iUFhA7nROS5qb0911yX 0yR5u7445w1wNoRlnZelsdBhZsRR8kXVjanZq+Hs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 09/31] net: Fix a data-race around sysctl_net_busy_poll. Date: Fri, 2 Sep 2022 14:18:35 +0200 Message-Id: <20220902121357.096918197@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220902121356.732130937@linuxfoundation.org> References: <20220902121356.732130937@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit c42b7cddea47503411bfb5f2f93a4154aaffa2d9 ] While reading sysctl_net_busy_poll, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 060212928670 ("net: add low latency socket poll") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/busy_poll.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h index 2fbeb1313c0f4..e522187cb6935 100644 --- a/include/net/busy_poll.h +++ b/include/net/busy_poll.h @@ -39,7 +39,7 @@ extern unsigned int sysctl_net_busy_poll __read_mostly; static inline bool net_busy_loop_on(void) { - return sysctl_net_busy_poll; + return READ_ONCE(sysctl_net_busy_poll); } static inline u64 busy_loop_us_clock(void) -- 2.35.1