From nobody Fri Dec 19 07:46:23 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 7EF34C3F6B0 for ; Mon, 1 Aug 2022 12:02:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232644AbiHAMCV (ORCPT ); Mon, 1 Aug 2022 08:02:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232308AbiHAMAc (ORCPT ); Mon, 1 Aug 2022 08:00:32 -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 7D58A4E61A; Mon, 1 Aug 2022 04:52:59 -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 0F970612C6; Mon, 1 Aug 2022 11:52:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B1F9C433C1; Mon, 1 Aug 2022 11:52:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354778; bh=TV9or4cVvHCFAXczizAjkTsOYTGZ/NNgwRCztI24QcE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W30yFdZF0Ut5kU7gWtARFOjGXJKrcQ0NzRU9Nyk9E8nLusFbq7uU9Aq1ACvViTf0v YJnvoJjorUYcP+oiGEvto5nPYzr889a3829saNszQX78VWxcRJtUHmhxk1kfwlBs8N oIZfq7hqoKzL3uyGEJL5lBjvyn5a9nmcYq+DyH3k= 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 5.15 17/69] tcp: Fix a data-race around sysctl_tcp_frto. Date: Mon, 1 Aug 2022 13:46:41 +0200 Message-Id: <20220801114135.185605997@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 commit 706c6202a3589f290e1ef9be0584a8f4a3cc0507 upstream. While reading sysctl_tcp_frto, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2167,7 +2167,7 @@ void tcp_enter_loss(struct sock *sk) * loss recovery is underway except recurring timeout(s) on * the same SND.UNA (sec 3.2). Disable F-RTO on path MTU probing */ - tp->frto =3D net->ipv4.sysctl_tcp_frto && + tp->frto =3D READ_ONCE(net->ipv4.sysctl_tcp_frto) && (new_recovery || icsk->icsk_retransmits) && !inet_csk(sk)->icsk_mtup.probe_size; }