From nobody Wed Sep 3 01:58:51 2025 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 8169CECAAD5 for ; Fri, 2 Sep 2022 12:51:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237851AbiIBMvg (ORCPT ); Fri, 2 Sep 2022 08:51:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237785AbiIBMun (ORCPT ); Fri, 2 Sep 2022 08:50:43 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C16E2F72EA; Fri, 2 Sep 2022 05:36:55 -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 05F2CB82A8B; Fri, 2 Sep 2022 12:24:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50201C433C1; Fri, 2 Sep 2022 12:24:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662121486; bh=BVmSj4j2lKWMzSNLk4z5AdM2bjhzmLxnEzZSY88b4KU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pljeTm/vK7m0na7EMDzPKf70UEtlK562dqIpGPRl98NV14rKUZ8mbEIJ86z1CW98J okbmWAwOFCsVA+JQ8Plu1gSVU43Ui0qsZG5L7ytvKMJ7unIEBMWJ3WWHo5p9fkvEdo nf0w9DLSRwoBuwPZAeEgrbk6gX8w3pOfM7E1y+N4= 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 4.19 23/56] net: Fix a data-race around sysctl_net_busy_poll. Date: Fri, 2 Sep 2022 14:18:43 +0200 Message-Id: <20220902121400.993054915@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220902121400.219861128@linuxfoundation.org> References: <20220902121400.219861128@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 c76a5e9894dac..8f42f6f3af86f 100644 --- a/include/net/busy_poll.h +++ b/include/net/busy_poll.h @@ -43,7 +43,7 @@ extern unsigned int sysctl_net_busy_poll __read_mostly; =20 static inline bool net_busy_loop_on(void) { - return sysctl_net_busy_poll; + return READ_ONCE(sysctl_net_busy_poll); } =20 static inline bool sk_can_busy_loop(const struct sock *sk) --=20 2.35.1