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 E5FB5C072A2 for ; Wed, 15 Nov 2023 20:44:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233403AbjKOUog (ORCPT ); Wed, 15 Nov 2023 15:44:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233492AbjKOUog (ORCPT ); Wed, 15 Nov 2023 15:44:36 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FBF0125 for ; Wed, 15 Nov 2023 12:44:32 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86162C433C7; Wed, 15 Nov 2023 20:44:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700081071; bh=FEElsma4a6VmbKraRQhOVhD1DjHzD+pqzrLXAkSuGw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KJ9OcRDtCGqAysYvqGGH02pUinxPq4crab6qRX5CATKrQJEHvKhAdvOb984Go2PvP sI4ciXxXrlFS/yqG2+AEc9f+93MTNhHVEzGJoysUWsIOuiu/tkx50JHDq6dzkNy62w ZOkQC6xckfhnAFhyR+Ok18qsCXWRW60MOBS1Ycpo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Neal Cardwell , Paolo Abeni , Sasha Levin Subject: [PATCH 4.19 04/88] tcp_metrics: add missing barriers on delete Date: Wed, 15 Nov 2023 15:35:16 -0500 Message-ID: <20231115191426.451031144@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191426.221330369@linuxfoundation.org> References: <20231115191426.221330369@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit cbc3a153222805d65f821e10f4f78b6afce06f86 ] When removing an item from RCU protected list, we must prevent store-tearing, using rcu_assign_pointer() or WRITE_ONCE(). Fixes: 04f721c671656 ("tcp_metrics: Rewrite tcp_metrics_flush_all") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Acked-by: Neal Cardwell Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv4/tcp_metrics.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 7bbd9125b5000..9ad4258cfcbcc 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -913,7 +913,7 @@ static void tcp_metrics_flush_all(struct net *net) match = net ? net_eq(tm_net(tm), net) : !refcount_read(&tm_net(tm)->count); if (match) { - *pp = tm->tcpm_next; + rcu_assign_pointer(*pp, tm->tcpm_next); kfree_rcu(tm, rcu_head); } else { pp = &tm->tcpm_next; @@ -954,7 +954,7 @@ static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info) if (addr_same(&tm->tcpm_daddr, &daddr) && (!src || addr_same(&tm->tcpm_saddr, &saddr)) && net_eq(tm_net(tm), net)) { - *pp = tm->tcpm_next; + rcu_assign_pointer(*pp, tm->tcpm_next); kfree_rcu(tm, rcu_head); found = true; } else { -- 2.42.0