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=-9.8 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 7FE75C32771 for ; Mon, 20 Jan 2020 22:12:30 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E623C217F4 for ; Mon, 20 Jan 2020 22:12:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E623C217F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 481mB32PF8zDqfy for ; Tue, 21 Jan 2020 09:12:27 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=tyreld@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 481m7m23FKzDqdm for ; Tue, 21 Jan 2020 09:10:28 +1100 (AEDT) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 00KM7Iqr175851; Mon, 20 Jan 2020 17:10:18 -0500 Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0b-001b2d01.pphosted.com with ESMTP id 2xmg3a9prg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 20 Jan 2020 17:10:17 -0500 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 00KM8s9Q030766; Mon, 20 Jan 2020 22:10:17 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma04wdc.us.ibm.com with ESMTP id 2xksn66ck1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 20 Jan 2020 22:10:17 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 00KMAGM842008842 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 20 Jan 2020 22:10:16 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 914D7AE0F2; Mon, 20 Jan 2020 22:10:16 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F1881AE0F4; Mon, 20 Jan 2020 22:10:13 +0000 (GMT) Received: from oc6857751186.ibm.com (unknown [9.160.26.151]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 20 Jan 2020 22:10:13 +0000 (GMT) From: Tyrel Datwyler To: mpe@ellerman.id.au Subject: [PATCH] powerpc/pseries/vio: Fix iommu_table use-after-free refcount warning Date: Mon, 20 Jan 2020 14:10:02 -0800 Message-Id: <1579558202-26052-1-git-send-email-tyreld@linux.ibm.com> X-Mailer: git-send-email 1.8.3.1 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.572 definitions=2020-01-20_10:2020-01-20, 2020-01-20 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1011 spamscore=0 impostorscore=0 phishscore=0 malwarescore=0 suspectscore=3 lowpriorityscore=0 adultscore=0 mlxscore=0 priorityscore=1501 mlxlogscore=815 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-2001200185 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tyrel Datwyler , aik@ozlabs.ru, Tyrel Datwyler , drt@linux.ibm.com, linuxppc-dev@lists.ozlabs.org, david@gibson.dropbear.id.au Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Tyrel Datwyler Commit e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") missed an iommu_table allocation in the pseries vio code. The iommu_table is allocated with kzalloc and as a result the associated kref gets a value of zero. This has the side effect that during a DLPAR remove of the associated virtual IOA the iommu_tce_table_put() triggers a use-after-free underflow warning. Call Trace: [c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190 (unreliable) [c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0 [c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70 [c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0 [c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240 [c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40 [c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250 [c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0 [c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60 [c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0 [c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260 [c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70 [c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250 [c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120 [c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68 Further, since the refcount was always zero the iommu_tce_table_put() fails to call the iommu_table release function resulting in a leak. Fix this issue be initilizing the iommu_table kref immediately after allocation. Fixes: e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") Signed-off-by: Tyrel Datwyler --- arch/powerpc/platforms/pseries/vio.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c index 79e2287..f682b7b 100644 --- a/arch/powerpc/platforms/pseries/vio.c +++ b/arch/powerpc/platforms/pseries/vio.c @@ -1176,6 +1176,8 @@ static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev) if (tbl == NULL) return NULL; + kref_init(&tbl->it_kref); + of_parse_dma_window(dev->dev.of_node, dma_window, &tbl->it_index, &offset, &size); -- 1.8.3.1