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 350B7C19F29 for ; Mon, 1 Aug 2022 11:49:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231668AbiHALtE (ORCPT ); Mon, 1 Aug 2022 07:49:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231649AbiHALsq (ORCPT ); Mon, 1 Aug 2022 07:48:46 -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 2C0663719D; Mon, 1 Aug 2022 04:48:22 -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 566B5612D0; Mon, 1 Aug 2022 11:48:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63762C433D6; Mon, 1 Aug 2022 11:48:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354500; bh=3sCoI8BpI7uF1zU0CY9LpPBLBwBcSwpqFOjuvTAicaU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ga/4Ikto6Egz8s1AyZ4vsWvKXOpdwc/dxZvK9u5w/QpqeKwi4ZcYyRGLIxMQedCos 2K9t5ZTs4XOcdNm4sF0abBrqpy8iQOXh1nfXCdmoATb5Txmy+FlTvufKn0cDxEZP+N 2Y/Qq7dxhpPOHYlPTc1QGhuh3Mpouxf+sR29t3Aw= 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 5.4 18/34] tcp: Fix a data-race around sysctl_tcp_min_tso_segs. Date: Mon, 1 Aug 2022 13:46:58 +0200 Message-Id: <20220801114128.744393211@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 [ Upstream commit e0bb4ab9dfddd872622239f49fb2bd403b70853b ] While reading sysctl_tcp_min_tso_segs, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 95bd09eb2750 ("tcp: TSO packets automatic sizing") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 99e077422975..ef749a47768a 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1761,7 +1761,7 @@ static u32 tcp_tso_segs(struct sock *sk, unsigned int mss_now) min_tso = ca_ops->min_tso_segs ? ca_ops->min_tso_segs(sk) : - sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs; + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs); tso_segs = tcp_tso_autosize(sk, mss_now, min_tso); return min_t(u32, tso_segs, sk->sk_gso_max_segs); -- 2.35.1