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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA66AC32789 for ; Fri, 2 Nov 2018 18:44:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90C2520862 for ; Fri, 2 Nov 2018 18:44:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="emUTlNy5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 90C2520862 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730105AbeKCDxG (ORCPT ); Fri, 2 Nov 2018 23:53:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:48590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729136AbeKCDxF (ORCPT ); Fri, 2 Nov 2018 23:53:05 -0400 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CC68F20866; Fri, 2 Nov 2018 18:44:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541184292; bh=rwBYUjk3+Y885THj6O7mHQnAPLPbHAZcxkkBonNHu6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=emUTlNy5v/Gm87L302tW4MnE+5ibudT3YQalg9OSkVvMDrbg9qF43PD/ebS1QOKM5 aQElUvzh5RGvnj4LPCxl3t8GJrCVVGpZ1MTG7CSqQ2B84SrY6neJ+3lCr5sxkzhIYr cbevTYGiRVjE6wAw/mh3aU++KcntZBSG2rMAeCQA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tung Nguyen , Jon Maloy , "David S. Miller" Subject: [PATCH 4.18 118/150] tipc: fix unsafe rcu locking when accessing publication list Date: Fri, 2 Nov 2018 19:34:40 +0100 Message-Id: <20181102182911.272834121@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181102182902.250560510@linuxfoundation.org> References: <20181102182902.250560510@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tung Nguyen [ Upstream commit d3092b2efca1cd1d492d0b08499a2066c5ca8cec ] The binding table's 'cluster_scope' list is rcu protected to handle races between threads changing the list and those traversing the list at the same moment. We have now found that the function named_distribute() uses the regular list_for_each() macro to traverse the said list. Likewise, the function tipc_named_withdraw() is removing items from the same list using the regular list_del() call. When these two functions execute in parallel we see occasional crashes. This commit fixes this by adding the missing _rcu() suffixes. Signed-off-by: Tung Nguyen Signed-off-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/name_distr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/tipc/name_distr.c +++ b/net/tipc/name_distr.c @@ -115,7 +115,7 @@ struct sk_buff *tipc_named_withdraw(stru struct sk_buff *buf; struct distr_item *item; - list_del(&publ->binding_node); + list_del_rcu(&publ->binding_node); if (publ->scope == TIPC_NODE_SCOPE) return NULL; @@ -147,7 +147,7 @@ static void named_distribute(struct net ITEM_SIZE) * ITEM_SIZE; u32 msg_rem = msg_dsz; - list_for_each_entry(publ, pls, binding_node) { + list_for_each_entry_rcu(publ, pls, binding_node) { /* Prepare next buffer: */ if (!skb) { skb = named_prepare_buf(net, PUBLICATION, msg_rem,