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 897E1C04A68 for ; Wed, 27 Jul 2022 17:16:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241665AbiG0RQE (ORCPT ); Wed, 27 Jul 2022 13:16:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241782AbiG0ROa (ORCPT ); Wed, 27 Jul 2022 13:14:30 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 461415B7BC; Wed, 27 Jul 2022 09:42:45 -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 BFB2CB821D5; Wed, 27 Jul 2022 16:42:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11619C433D6; Wed, 27 Jul 2022 16:42:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658940163; bh=GbhDpoG66pcZmVI2I4jhiCBBRcEPAZrdFjjlqZK29js=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=y2f+EnYCY/WT20t3SzQE2W7+qccdVHQYfytiIM0WHEaL4X0CFm2tT/T0pZB9aiuVs 4zWtUckVC5z45/FdFGQJTkvDUrrnV9EPeJJsxMcTrUKID2LTufMVFpBEeSPmRLB+77 GTc2/EbHPxQC2pleDHYGQpyXyOrmzdMEvWdFGU4A= 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 5.15 127/201] tcp: Fix a data-race around sysctl_tcp_stdurg. Date: Wed, 27 Jul 2022 18:10:31 +0200 Message-Id: <20220727161033.027113259@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161026.977588183@linuxfoundation.org> References: <20220727161026.977588183@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 4e08ed41cb1194009fc1a916a59ce3ed4afd77cd ] While reading sysctl_tcp_stdurg, 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: 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 1cc0aca39c04..6309a4eb3acd 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5542,7 +5542,7 @@ static void tcp_check_urg(struct sock *sk, const struct tcphdr *th) struct tcp_sock *tp = tcp_sk(sk); u32 ptr = ntohs(th->urg_ptr); - if (ptr && !sock_net(sk)->ipv4.sysctl_tcp_stdurg) + if (ptr && !READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_stdurg)) ptr--; ptr += ntohl(th->seq); -- 2.35.1