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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BB3D7C4338F for ; Tue, 3 Aug 2021 12:47:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A30A660F94 for ; Tue, 3 Aug 2021 12:47:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235994AbhHCMr7 (ORCPT ); Tue, 3 Aug 2021 08:47:59 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:16038 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236107AbhHCMrM (ORCPT ); Tue, 3 Aug 2021 08:47:12 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GfF0Z5VF9zZwLc; Tue, 3 Aug 2021 20:43:26 +0800 (CST) Received: from dggpeml500017.china.huawei.com (7.185.36.243) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Tue, 3 Aug 2021 20:46:59 +0800 Received: from huawei.com (10.175.103.91) by dggpeml500017.china.huawei.com (7.185.36.243) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Tue, 3 Aug 2021 20:46:59 +0800 From: Yang Yingliang To: , , CC: , , , , Subject: [PATCH 4.19 2/2] padata: add separate cpuhp node for CPUHP_PADATA_DEAD Date: Tue, 3 Aug 2021 20:53:01 +0800 Message-ID: <20210803125301.77629-3-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210803125301.77629-1-yangyingliang@huawei.com> References: <20210803125301.77629-1-yangyingliang@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.103.91] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500017.china.huawei.com (7.185.36.243) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Jordan [ Upstream commit 3c2214b6027ff37945799de717c417212e1a8c54 ] Removing the pcrypt module triggers this: general protection fault, probably for non-canonical address 0xdead000000000122 CPU: 5 PID: 264 Comm: modprobe Not tainted 5.6.0+ #2 Hardware name: QEMU Standard PC RIP: 0010:__cpuhp_state_remove_instance+0xcc/0x120 Call Trace: padata_sysfs_release+0x74/0xce kobject_put+0x81/0xd0 padata_free+0x12/0x20 pcrypt_exit+0x43/0x8ee [pcrypt] padata instances wrongly use the same hlist node for the online and dead states, so __padata_free()'s second cpuhp remove call chokes on the node that the first poisoned. cpuhp multi-instance callbacks only walk forward in cpuhp_step->list and the same node is linked in both the online and dead lists, so the list corruption that results from padata_alloc() adding the node to a second list without removing it from the first doesn't cause problems as long as no instances are freed. Avoid the issue by giving each state its own node. Fixes: 894c9ef9780c ("padata: validate cpumask without removed CPU during offline") Signed-off-by: Daniel Jordan Cc: Herbert Xu Cc: Steffen Klassert Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Herbert Xu Signed-off-by: Yang Yingliang --- include/linux/padata.h | 6 ++++-- kernel/padata.c | 14 ++++++++------ 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/include/linux/padata.h b/include/linux/padata.h index d803397a28f70..8c9827cc63747 100644 --- a/include/linux/padata.h +++ b/include/linux/padata.h @@ -138,7 +138,8 @@ struct parallel_data { /** * struct padata_instance - The overall control structure. * - * @cpu_notifier: cpu hotplug notifier. + * @cpu_online_node: Linkage for CPU online callback. + * @cpu_dead_node: Linkage for CPU offline callback. * @wq: The workqueue in use. * @pd: The internal control structure. * @cpumask: User supplied cpumasks for parallel and serial works. @@ -150,7 +151,8 @@ struct parallel_data { * @flags: padata flags. */ struct padata_instance { - struct hlist_node node; + struct hlist_node cpu_online_node; + struct hlist_node cpu_dead_node; struct workqueue_struct *wq; struct parallel_data *pd; struct padata_cpumask cpumask; diff --git a/kernel/padata.c b/kernel/padata.c index 4401b4f13d0be..7f2b6d369fd47 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -748,7 +748,7 @@ static int padata_cpu_online(unsigned int cpu, struct hlist_node *node) struct padata_instance *pinst; int ret; - pinst = hlist_entry_safe(node, struct padata_instance, node); + pinst = hlist_entry_safe(node, struct padata_instance, cpu_online_node); if (!pinst_has_cpu(pinst, cpu)) return 0; @@ -763,7 +763,7 @@ static int padata_cpu_dead(unsigned int cpu, struct hlist_node *node) struct padata_instance *pinst; int ret; - pinst = hlist_entry_safe(node, struct padata_instance, node); + pinst = hlist_entry_safe(node, struct padata_instance, cpu_dead_node); if (!pinst_has_cpu(pinst, cpu)) return 0; @@ -779,8 +779,9 @@ static enum cpuhp_state hp_online; static void __padata_free(struct padata_instance *pinst) { #ifdef CONFIG_HOTPLUG_CPU - cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, &pinst->node); - cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node); + cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, + &pinst->cpu_dead_node); + cpuhp_state_remove_instance_nocalls(hp_online, &pinst->cpu_online_node); #endif padata_stop(pinst); @@ -964,9 +965,10 @@ static struct padata_instance *padata_alloc(struct workqueue_struct *wq, mutex_init(&pinst->lock); #ifdef CONFIG_HOTPLUG_CPU - cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->node); + cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, + &pinst->cpu_online_node); cpuhp_state_add_instance_nocalls_cpuslocked(CPUHP_PADATA_DEAD, - &pinst->node); + &pinst->cpu_dead_node); #endif return pinst; -- 2.25.1