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, URIBL_BLOCKED,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 DC81BC28CC2 for ; Fri, 31 May 2019 09:21:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF72D266AA for ; Fri, 31 May 2019 09:21:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727064AbfEaJVS (ORCPT ); Fri, 31 May 2019 05:21:18 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:17635 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726232AbfEaJVR (ORCPT ); Fri, 31 May 2019 05:21:17 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 1E44ABCCF2B6157DC235; Fri, 31 May 2019 17:21:14 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.439.0; Fri, 31 May 2019 17:21:08 +0800 From: Kefeng Wang To: Steffen Klassert , Herbert Xu , "David S. Miller" CC: , , "Kefeng Wang" , Hulk Robot Subject: [PATCH] crypto: pcrypt: Fix possible deadlock in padata_sysfs_release Date: Fri, 31 May 2019 17:29:23 +0800 Message-ID: <20190531092923.4874-1-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.20.1 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-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@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 | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index 0e9ce329fd47..662228b48b70 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -407,13 +407,14 @@ 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) goto err_destroy_workqueue; @@ -448,12 +449,11 @@ 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