From nobody Fri Dec 19 07:47:29 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 41D68C00144 for ; Mon, 1 Aug 2022 12:05:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233412AbiHAMF3 (ORCPT ); Mon, 1 Aug 2022 08:05:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233394AbiHAMEt (ORCPT ); Mon, 1 Aug 2022 08:04:49 -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 17DE03D5A4; Mon, 1 Aug 2022 04:54:35 -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 9727CB81177; Mon, 1 Aug 2022 11:54:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAB33C433C1; Mon, 1 Aug 2022 11:54:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354872; bh=kqzAiSw/ct00EXWfjflkwgRWQcWUPImEYu8EiAWgWrI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zJf4oWiWCraq3i2gv3sP6u91nhNnCfTTSySWCtJwMVv2Ty6bYagKzINLYUpkDFGHH v7jz1AOUVOJG9qFVhwiIjnEUK5Hnpq6q/dVsUMTSODsWuh8bjN3oGZ8RPrLyqhrzB1 dlyyi2IZcBhPhnp7k7jjeOxEwS7ml1gaq/qT6ngk= 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 5.15 51/69] tcp: Fix a data-race around sysctl_tcp_comp_sack_nr. Date: Mon, 1 Aug 2022 13:47:15 +0200 Message-Id: <20220801114136.538559950@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114134.468284027@linuxfoundation.org> References: <20220801114134.468284027@linuxfoundation.org> User-Agent: quilt/0.66 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 79f55473bfc8ac51bd6572929a679eeb4da22251 ] While reading sysctl_tcp_comp_sack_nr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 9c21d2fc41c0 ("tcp: add tcp_comp_sack_nr sysctl") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7b593865b4ae..a33e6aa42a4c 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5491,7 +5491,7 @@ static void __tcp_ack_snd_check(struct sock *sk, int = ofo_possible) } =20 if (!tcp_is_sack(tp) || - tp->compressed_ack >=3D sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr) + tp->compressed_ack >=3D READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_= sack_nr)) goto send_now; =20 if (tp->compressed_ack_rcv_nxt !=3D tp->rcv_nxt) { --=20 2.35.1