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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 BFED5C04ABB for ; Thu, 13 Sep 2018 13:44:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82AAF20854 for ; Thu, 13 Sep 2018 13:44:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82AAF20854 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 S1730046AbeIMSyL (ORCPT ); Thu, 13 Sep 2018 14:54:11 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60582 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728565AbeIMSyK (ORCPT ); Thu, 13 Sep 2018 14:54:10 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0F640D10; Thu, 13 Sep 2018 13:44:36 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jamal Hadi Salim , Cong Wang , "David S. Miller" Subject: [PATCH 4.14 019/115] act_ife: fix a potential deadlock Date: Thu, 13 Sep 2018 15:30:39 +0200 Message-Id: <20180913131824.703629451@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180913131823.327472833@linuxfoundation.org> References: <20180913131823.327472833@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 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cong Wang [ Upstream commit 5ffe57da29b3802baeddaa40909682bbb4cb4d48 ] use_all_metadata() acquires read_lock(&ife_mod_lock), then calls add_metainfo() which calls find_ife_oplist() which acquires the same lock again. Deadlock! Introduce __add_metainfo() which accepts struct tcf_meta_ops *ops as an additional parameter and let its callers to decide how to find it. For use_all_metadata(), it already has ops, no need to find it again, just call __add_metainfo() directly. And, as ife_mod_lock is only needed for find_ife_oplist(), this means we can make non-atomic allocation for populate_metalist() now. Fixes: 817e9f2c5c26 ("act_ife: acquire ife_mod_lock before reading ifeoplist") Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/act_ife.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) --- a/net/sched/act_ife.c +++ b/net/sched/act_ife.c @@ -278,22 +278,16 @@ static int load_metaops_and_vet(u32 meta /* called when adding new meta information */ -static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval, - int len, bool atomic, bool exists) +static int __add_metainfo(const struct tcf_meta_ops *ops, + struct tcf_ife_info *ife, u32 metaid, void *metaval, + int len, bool atomic, bool exists) { struct tcf_meta_info *mi = NULL; - struct tcf_meta_ops *ops = find_ife_oplist(metaid); int ret = 0; - if (!ops) - return -ENOENT; - mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL); - if (!mi) { - /*put back what find_ife_oplist took */ - module_put(ops->owner); + if (!mi) return -ENOMEM; - } mi->metaid = metaid; mi->ops = ops; @@ -301,7 +295,6 @@ static int add_metainfo(struct tcf_ife_i ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL); if (ret != 0) { kfree(mi); - module_put(ops->owner); return ret; } } @@ -315,6 +308,21 @@ static int add_metainfo(struct tcf_ife_i return ret; } +static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval, + int len, bool exists) +{ + const struct tcf_meta_ops *ops = find_ife_oplist(metaid); + int ret; + + if (!ops) + return -ENOENT; + ret = __add_metainfo(ops, ife, metaid, metaval, len, false, exists); + if (ret) + /*put back what find_ife_oplist took */ + module_put(ops->owner); + return ret; +} + static int use_all_metadata(struct tcf_ife_info *ife, bool exists) { struct tcf_meta_ops *o; @@ -323,7 +331,7 @@ static int use_all_metadata(struct tcf_i read_lock(&ife_mod_lock); list_for_each_entry(o, &ifeoplist, list) { - rc = add_metainfo(ife, o->metaid, NULL, 0, true, exists); + rc = __add_metainfo(o, ife, o->metaid, NULL, 0, true, exists); if (rc == 0) installed += 1; } @@ -412,7 +420,7 @@ static int populate_metalist(struct tcf_ if (rc != 0) return rc; - rc = add_metainfo(ife, i, val, len, false, exists); + rc = add_metainfo(ife, i, val, len, exists); if (rc) return rc; }