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[23.128.96.18]) by mx.google.com with ESMTP id i10si3502897edb.37.2020.09.10.10.19.54; Thu, 10 Sep 2020 10:20:19 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2020-01-29 header.b=hweQM1Dm; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725935AbgIJRTO (ORCPT + 99 others); Thu, 10 Sep 2020 13:19:14 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:37890 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726434AbgIJRSr (ORCPT ); Thu, 10 Sep 2020 13:18:47 -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 08AHE3DU150208; Thu, 10 Sep 2020 17:18:37 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2020-01-29; bh=mtTRYf8cW9IrGv5hxQTD9YTSb1RZGlhCqY0Rw3OKHlQ=; b=hweQM1DmWcaSr+g9POWlAgCdNd5+LyQS/OpQNKcP71S985+9AtQDkn69baMqr6RUpB86 NpS9Eaek2h4t0ElK+pVJcNtq+gsqo8vTL0VHKwQOx2TpOVUQdGF1YkQLX7DTPeBXOvGt OTWItZggZPSHHdTOmey73W+TOlfRqWSYYLH8xF7/h5no0a8rIrNqa0Y98m6jHoBUIdjT SiV66On+LrTHXkaSQhk8o+k/4d2bMPfgETdAadF4COLb7KRRdblxjIxuqL0QYk2qzJx8 arHi2jEaLMHEUtkz38xkw7vtgRH1crifTgptu0hsuoOgo2IJ7GfT9yfEQmbXm2lbHiHv 7A== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 33c3an9e7a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 10 Sep 2020 17:18:37 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08AHFYQ8123309; Thu, 10 Sep 2020 17:16:37 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 33cmevb23q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Sep 2020 17:16:37 +0000 Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 08AHGW26013722; Thu, 10 Sep 2020 17:16:33 GMT Received: from paddy.uk.oracle.com (/10.175.191.159) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 10 Sep 2020 10:16:32 -0700 From: Joao Martins To: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: Dan Carpenter , Suravee Suthikulpanit , Joerg Roedel Subject: [PATCH] iommu/amd: Fix potential @entry null deref Date: Thu, 10 Sep 2020 18:16:21 +0100 Message-Id: <20200910171621.12879-1-joao.m.martins@oracle.com> X-Mailer: git-send-email 2.11.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9740 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=8 adultscore=0 bulkscore=0 phishscore=0 malwarescore=0 mlxlogscore=999 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009100159 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9740 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 priorityscore=1501 clxscore=1015 bulkscore=0 malwarescore=0 lowpriorityscore=0 mlxlogscore=999 suspectscore=8 adultscore=0 mlxscore=0 impostorscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009100159 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After commit 26e495f34107 ("iommu/amd: Restore IRTE.RemapEn bit after programming IRTE"), smatch warns: drivers/iommu/amd/iommu.c:3870 amd_iommu_deactivate_guest_mode() warn: variable dereferenced before check 'entry' (see line 3867) Fix this by moving the @valid assignment to after @entry has been checked for NULL. Cc: Suravee Suthikulpanit Fixes: 26e495f34107 ("iommu/amd: Restore IRTE.RemapEn bit after programming IRTE") Reported-by: Dan Carpenter Signed-off-by: Joao Martins --- drivers/iommu/amd/iommu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 07ae8b93887e..8abe1c7ad45b 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -3864,12 +3864,14 @@ int amd_iommu_deactivate_guest_mode(void *data) struct amd_ir_data *ir_data = (struct amd_ir_data *)data; struct irte_ga *entry = (struct irte_ga *) ir_data->entry; struct irq_cfg *cfg = ir_data->cfg; - u64 valid = entry->lo.fields_remap.valid; + u64 valid; if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) || !entry || !entry->lo.fields_vapic.guest_mode) return 0; + valid = entry->lo.fields_remap.valid; + entry->lo.val = 0; entry->hi.val = 0; -- 2.17.1