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 6B4E2C04A68 for ; Wed, 27 Jul 2022 17:41:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242451AbiG0RlU (ORCPT ); Wed, 27 Jul 2022 13:41:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242810AbiG0Rkp (ORCPT ); Wed, 27 Jul 2022 13:40:45 -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 B5E9B88E1B; Wed, 27 Jul 2022 09:51:29 -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 AAED4B821D6; Wed, 27 Jul 2022 16:51:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EFBF4C433D6; Wed, 27 Jul 2022 16:51:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658940684; bh=BXt+/DsJ/RD7ujmlAfRZ6rwtE/OfsSQKVIpcz+npSWo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vysvOr33iYHn8MCKsKi8B//k49kGUAlegBwDkxfPO/2P5n+D8pT6eG7KBbEa5etjU rKVxUSBqx20KWNgB/BGhk6Ux9PNujykeoOkpdNg5WyGmTH4wRpXXiusnZACWqm1JIl 4mAo7Mz3yqZC2Epy71UJZfkiBiA9hHJwl9cgaY0Q= 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 5.18 112/158] ipv4: Fix a data-race around sysctl_fib_multipath_use_neigh. Date: Wed, 27 Jul 2022 18:12:56 +0200 Message-Id: <20220727161025.969819245@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161021.428340041@linuxfoundation.org> References: <20220727161021.428340041@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 87507bcb4f5de16bb419e9509d874f4db6c0ad0f ] While reading sysctl_fib_multipath_use_neigh, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: a6db4494d218 ("net: ipv4: Consider failed nexthops in multipath routes") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/fib_semantics.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 720f65f7bd0b..9f5c1c26c8f2 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -2216,7 +2216,7 @@ void fib_select_multipath(struct fib_result *res, int hash) } change_nexthops(fi) { - if (net->ipv4.sysctl_fib_multipath_use_neigh) { + if (READ_ONCE(net->ipv4.sysctl_fib_multipath_use_neigh)) { if (!fib_good_nh(nexthop_nh)) continue; if (!first) { -- 2.35.1