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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 4B972C28CC1 for ; Sat, 1 Jun 2019 09:15:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 245D6270DD for ; Sat, 1 Jun 2019 09:15:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726839AbfFAJPh (ORCPT ); Sat, 1 Jun 2019 05:15:37 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:45048 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726134AbfFAJPg (ORCPT ); Sat, 1 Jun 2019 05:15:36 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 85489C906D572A0C7651; Sat, 1 Jun 2019 17:15:34 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.439.0; Sat, 1 Jun 2019 17:15:25 +0800 From: Kefeng Wang To: Steffen Klassert , Herbert Xu , "David S. Miller" CC: , , Kefeng Wang , Hulk Robot Subject: [PATCH v2] crypto: pcrypt: Fix possible deadlock in padata_sysfs_release Date: Sat, 1 Jun 2019 17:23:32 +0800 Message-ID: <20190601092332.136481-1-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <1b71b136-3501-db1c-834b-ba7ed1431f4d@huawei.com> References: <1b71b136-3501-db1c-834b-ba7ed1431f4d@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a deadlock issue in pcrypt_init_padata(), pcrypt_init_padata() cpus_read_lock() padata_free() padata_sysfs_release() cpus_read_lock() Narrow rcu_read_lock/unlock() and move put_online_cpus() before padata_free() to fix it. Reported-by: Hulk Robot Signed-off-by: Kefeng Wang --- crypto/pcrypt.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index 0e9ce329fd47..f3dacb714cd4 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -407,16 +407,19 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt, int ret = -ENOMEM; struct pcrypt_cpumask *mask; - get_online_cpus(); pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE, 1, name); if (!pcrypt->wq) goto err; + get_online_cpus(); + pcrypt->pinst = padata_alloc_possible(pcrypt->wq); - if (!pcrypt->pinst) + if (!pcrypt->pinst) { + put_online_cpus(); goto err_destroy_workqueue; + } mask = kmalloc(sizeof(*mask), GFP_KERNEL); if (!mask) @@ -448,12 +451,11 @@ static int pcrypt_init_padata(struct padata_pcrypt *pcrypt, free_cpumask_var(mask->mask); kfree(mask); err_free_padata: + put_online_cpus(); padata_free(pcrypt->pinst); err_destroy_workqueue: destroy_workqueue(pcrypt->wq); err: - put_online_cpus(); - return ret; } -- 2.20.1