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 A1BC8C19F2D for ; Tue, 9 Aug 2022 18:03:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344542AbiHISDu (ORCPT ); Tue, 9 Aug 2022 14:03:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344414AbiHISC4 (ORCPT ); Tue, 9 Aug 2022 14:02:56 -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 E919C27177; Tue, 9 Aug 2022 11:01:39 -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 CAD9D61050; Tue, 9 Aug 2022 18:01:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E941C433D6; Tue, 9 Aug 2022 18:01:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660068099; bh=/2+d9OPR6NFLDRBEJdCKTHd7LGem0wQnA1LurVjf3iE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kaUcqYagmuoo9R3zvY7uGHtilVeOfWDbcRL0I9UqwmO2PjVlvXI3l2572OTaCSb1S XX2mrDFV3W6qHtyzriS6+ywz/yBKWl15B0PgUOA8GC1HEXswEcBBnWADPyRMSJvZPV XdQzcfoyqO0C1Yd2TVLGvBSV8u+19F5qIbK7gYEA= 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 4.19 04/32] tcp: Fix data-races around sysctl_tcp_dsack. Date: Tue, 9 Aug 2022 19:59:55 +0200 Message-Id: <20220809175513.231288785@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220809175513.082573955@linuxfoundation.org> References: <20220809175513.082573955@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 58ebb1c8b35a8ef38cd6927431e0fa7b173a632d upstream. While reading sysctl_tcp_dsack, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_input.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4197,7 +4197,7 @@ static void tcp_dsack_set(struct sock *s { struct tcp_sock *tp = tcp_sk(sk); - if (tcp_is_sack(tp) && sock_net(sk)->ipv4.sysctl_tcp_dsack) { + if (tcp_is_sack(tp) && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_dsack)) { int mib_idx; if (before(seq, tp->rcv_nxt)) @@ -4232,7 +4232,7 @@ static void tcp_send_dupack(struct sock NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOST); tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS); - if (tcp_is_sack(tp) && sock_net(sk)->ipv4.sysctl_tcp_dsack) { + if (tcp_is_sack(tp) && READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_dsack)) { u32 end_seq = TCP_SKB_CB(skb)->end_seq; if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))