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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 83E4CC38A2A for ; Fri, 8 May 2020 15:07:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60A382496B for ; Fri, 8 May 2020 15:07:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="Gwz1VLQA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727932AbgEHPHz (ORCPT ); Fri, 8 May 2020 11:07:55 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:47948 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726913AbgEHPHy (ORCPT ); Fri, 8 May 2020 11:07:54 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 048F7oj4126568; Fri, 8 May 2020 15:07:51 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2020-01-29; bh=ygriZszAK7uOqyWhz842ZZT0KgYajtrTrd4tzNFIj/0=; b=Gwz1VLQALtvp35MtFeGpQufTqn1dft1N2tri/H7KDUgJpn+hO0jTDG0JBpAEIfEScZRR xsuqcFHBfV8Z4F6aJELnyplEfgY6BTM/I58RHGPiI4PBM6vd4+UmDv1/sGZzjzPYT2Mu JzO5W4gqfsJIyPbY52IWIWDa01L99Uwr0ph3IrvO5i1gEQPHnV0d60hrce3ZmOc7rkDS O5zKK7NxAQfItqJv6VJ43Avm/kK95h8rBNUp5FEbqUKGfs0EhSVF4unu/VWhynfSwkD0 jwt5gdNBuNqQ3ToQsPqolj3qYOMlSTzWaOv89rQWjQE1l/5W2FueCWKUBYWe8GP3sBpR hQ== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2120.oracle.com with ESMTP id 30vtexug38-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 08 May 2020 15:07:50 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 048F6wb0129074; Fri, 8 May 2020 15:07:48 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3030.oracle.com with ESMTP id 30vtdnrwck-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 08 May 2020 15:07:47 +0000 Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 048F7lxK016233; Fri, 8 May 2020 15:07:47 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 08 May 2020 08:07:46 -0700 Date: Fri, 8 May 2020 18:07:40 +0300 From: Dan Carpenter To: Tejun Heo , Sean Fu Cc: Lai Jiangshan , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] workqueue: Fix an use after free in init_rescuer() Message-ID: <20200508150740.GA415175@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9614 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 spamscore=0 mlxscore=0 mlxlogscore=999 bulkscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005080135 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9614 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 adultscore=0 spamscore=0 suspectscore=0 bulkscore=0 priorityscore=1501 malwarescore=0 phishscore=0 impostorscore=0 mlxscore=0 mlxlogscore=999 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005080135 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We need to preserve error code before freeing "rescuer". Fixes: f187b6974f6df ("workqueue: Use IS_ERR and PTR_ERR instead of PTR_ERR_OR_ZERO.") Signed-off-by: Dan Carpenter --- Another option would be to just revert the original commit. kernel/workqueue.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ddf0537dce140..10ed8d761e0b7 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4197,6 +4197,7 @@ static int wq_clamp_max_active(int max_active, unsigned int flags, static int init_rescuer(struct workqueue_struct *wq) { struct worker *rescuer; + int ret; if (!(wq->flags & WQ_MEM_RECLAIM)) return 0; @@ -4208,8 +4209,9 @@ static int init_rescuer(struct workqueue_struct *wq) rescuer->rescue_wq = wq; rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", wq->name); if (IS_ERR(rescuer->task)) { + ret = PTR_ERR(rescuer->task); kfree(rescuer); - return PTR_ERR(rescuer->task); + return ret; } wq->rescuer = rescuer; -- 2.26.2