From patchwork Thu Dec 17 15:59:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Haberland X-Patchwork-Id: 11980145 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,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 2F7CFC4361B for ; Thu, 17 Dec 2020 16:01:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDA2A23975 for ; Thu, 17 Dec 2020 16:01:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726548AbgLQQBJ (ORCPT ); Thu, 17 Dec 2020 11:01:09 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:11354 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725871AbgLQQBJ (ORCPT ); Thu, 17 Dec 2020 11:01:09 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0BHFXWcL126119; Thu, 17 Dec 2020 11:00:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=pp1; bh=jtPki1yJhqps2YVLa9BpoClJ4eGOp1DNBdnx9Q8lDsk=; b=TAYGeu6LPYGX9olM78GwRqySQpdVJgnoH4WY4Dcb3VHQcknr8/RGiVE2kBKYda7TewFQ vPNJ+hJZLEOnxp4dc6HTUddWbVAG3m4XsWzEgamNAvBKVsJnlZjWWhzF80BhcoAPe71c NS3rp/RQzV2UxWrPNrkYxWN3a4+Vd1UlsR2XdGlfDNwOQyz+j7jAH9g655X3jfD7XKag ndggkJqPla/mNFeg580xP4xhiQcglKZYBSc3RrLgz5rWBMdhBGPJUvjy8NLBwJDfWMI/ sy4vt1uHwYVm+7sEJDUZOmLarhqkGqlHO8GoKlpnw5zUWit0xZHoRDulE4hPDgv91PFC 1A== Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 35ga0s8xfx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 17 Dec 2020 11:00:27 -0500 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0BHFrBuM023407; Thu, 17 Dec 2020 16:00:26 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma03fra.de.ibm.com with ESMTP id 35cng8g63d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 17 Dec 2020 16:00:25 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0BHFx7HY26083780 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 17 Dec 2020 15:59:07 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 98492AE055; Thu, 17 Dec 2020 15:59:07 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 846EDAE053; Thu, 17 Dec 2020 15:59:07 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 17 Dec 2020 15:59:07 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 20191) id 360F9E0399; Thu, 17 Dec 2020 16:59:07 +0100 (CET) From: Stefan Haberland To: Jens Axboe Cc: linux-block@vger.kernel.org, Jan Hoeppner , linux-s390@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Christian Borntraeger Subject: [PATCH 4/4] s390/dasd: fix list corruption of lcu list Date: Thu, 17 Dec 2020 16:59:07 +0100 Message-Id: <20201217155907.36436-5-sth@linux.ibm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201217155907.36436-1-sth@linux.ibm.com> References: <20201217155907.36436-1-sth@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343,18.0.737 definitions=2020-12-17_10:2020-12-15,2020-12-17 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 adultscore=0 lowpriorityscore=0 spamscore=0 bulkscore=0 mlxlogscore=953 phishscore=0 priorityscore=1501 suspectscore=0 clxscore=1015 mlxscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012170106 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org In dasd_alias_disconnect_device_from_lcu the device is removed from any list on the LCU. Afterwards the LCU is removed from the lcu list if it does not contain devices any longer. The lcu->lock protects the lcu from parallel updates. But to cancel all workers and wait for completion the lcu->lock has to be unlocked. If two devices are removed in parallel and both are removed from the LCU the first device that takes the lcu->lock again will delete the LCU because it is already empty but the second device also tries to free the LCU which leads to a list corruption of the lcu list. Fix by removing the device right before the lcu is checked without unlocking the lcu->lock in between. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner --- drivers/s390/block/dasd_alias.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index 60344e13e87b..dc78a523a69f 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -256,7 +256,6 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) return; device->discipline->get_uid(device, &uid); spin_lock_irqsave(&lcu->lock, flags); - list_del_init(&device->alias_list); /* make sure that the workers don't use this device */ if (device == lcu->suc_data.device) { spin_unlock_irqrestore(&lcu->lock, flags); @@ -283,6 +282,7 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) spin_lock_irqsave(&aliastree.lock, flags); spin_lock(&lcu->lock); + list_del_init(&device->alias_list); if (list_empty(&lcu->grouplist) && list_empty(&lcu->active_devices) && list_empty(&lcu->inactive_devices)) {