From patchwork Wed Sep 1 11:49:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alexander Bulekov X-Patchwork-Id: 1523106 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=bu.edu header.i=@bu.edu header.a=rsa-sha256 header.s=selector2 header.b=P0TlYCRU; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4H02Wt408qz9sRN for ; Wed, 1 Sep 2021 21:53:46 +1000 (AEST) Received: from localhost ([::1]:38986 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mLOoJ-0002Q1-6x for incoming@patchwork.ozlabs.org; Wed, 01 Sep 2021 07:53:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55212) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLOlM-00074J-0J for qemu-devel@nongnu.org; Wed, 01 Sep 2021 07:50:40 -0400 Received: from mail-bn7nam10on2134.outbound.protection.outlook.com ([40.107.92.134]:37985 helo=NAM10-BN7-obe.outbound.protection.outlook.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLOlK-0002UE-Gv for qemu-devel@nongnu.org; Wed, 01 Sep 2021 07:50:39 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=dmdTrVWBl/7+U0J4/iZHs611Dfq+UEwHeAhpUKKnX/4BscA1lfK9jrTVeva6e9G9axMBuo02/WSuv+wEGdX/EFAgSIzuRk3F5UvPXH3dPeeZKf68RENqwbGJJi86tsG9OUrT++JinPWW8hlJE+6YuSLug+7tzeEp5PEUXZ9xgcp/Y8/TrfH5P5F8Gc+YHaNJNP+3lo/zr4DCmUIRYP23clC4BUB8bof1s5RifHmU0hU0esYxMV1eGTmvrJIJvMPIX+ezgLSs8iaQK4o5ogv+gkFazmwUzuaKBAQ0uU5KKdtQjtZWIZBDs02zSHgRZXXQMvI5LjvL3IV6pJLhdCz50A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=aS6NVYFeWYkAUe+yX/SnynNsxZaFbZU5FDRzrN2qyKA=; b=WSVkcc1JIYkQQxbVg/STg9C79r/pTWxUyhpOi1q44vna23q4/Ee4/YMv+DSHze6zlFQJeLHNpeeCRsUnsAW+itb8pUeMHtwq2M/Hag1jiZM22oNYIyRWxzSZR3vPe0XCApq1cquMswHCwSkSZ40ZqlfH+Hn3Y5EqMGiUe3Sw0oLiAhXvxz7FUWG36OFyfKDF3d6YpOtoHacvwedf9lnzPO9pXspLtnnr2zxWk0/Sbt0/ovttg3ojqfQxGlNIn2nTelIQ4WtmN2kpDeytg9lfx5sZzremVzzb36sPydCOUdq3oFWu/rjT1pq9CIfj4Hl2fum/d1pYwgEPjkezFsQBkg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=bu.edu; dmarc=pass action=none header.from=bu.edu; dkim=pass header.d=bu.edu; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bu.edu; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=aS6NVYFeWYkAUe+yX/SnynNsxZaFbZU5FDRzrN2qyKA=; b=P0TlYCRUWAyAZCHc0ItfbNHQ8Acm4BfbH/p8rtxwMlDsawVhe4LJy0Ay9e6gQb1WStrVvt6GP+aAaK9t8F3Ua+8Cevl2gjIOtci/lHfY57I6gKt4smj4gbMO7syE9Tgnh/hkTPuaG8E+p6dLR9CWQi011WEc/JScYkrBLe7YJxE5py8592cAdyuVYiv94+8qACcN59Dj5W0pLREWoJhiEf4IZFhcTc5fVtdIu8fQwdFhAasCMXCbSAp6Isv+MV3fpraR6TVcIWRIoaOVZ1GGZSNVyApyrgNuNTrcs4MdNV5ybT7HEJCW8B1gENbpSSKjTgfe+omtuBt72h2Lqnw6Tg== Authentication-Results: nongnu.org; dkim=none (message not signed) header.d=none;nongnu.org; dmarc=none action=none header.from=bu.edu; Received: from SN6PR03MB3871.namprd03.prod.outlook.com (2603:10b6:805:6d::32) by SN6PR03MB4224.namprd03.prod.outlook.com (2603:10b6:805:ba::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4457.23; Wed, 1 Sep 2021 11:50:27 +0000 Received: from SN6PR03MB3871.namprd03.prod.outlook.com ([fe80::f6:2ec0:d576:8139]) by SN6PR03MB3871.namprd03.prod.outlook.com ([fe80::f6:2ec0:d576:8139%7]) with mapi id 15.20.4457.024; Wed, 1 Sep 2021 11:50:27 +0000 From: Alexander Bulekov To: qemu-devel@nongnu.org Subject: [PULL v3 1/8] fuzz: fix sparse memory access in the DMA callback Date: Wed, 1 Sep 2021 07:49:57 -0400 Message-Id: <20210901115004.34768-2-alxndr@bu.edu> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210901115004.34768-1-alxndr@bu.edu> References: <20210901115004.34768-1-alxndr@bu.edu> X-ClientProxiedBy: BL1PR13CA0328.namprd13.prod.outlook.com (2603:10b6:208:2c1::33) To SN6PR03MB3871.namprd03.prod.outlook.com (2603:10b6:805:6d::32) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from stormtrooper.vrmnet (72.74.210.193) by BL1PR13CA0328.namprd13.prod.outlook.com (2603:10b6:208:2c1::33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4478.8 via Frontend Transport; Wed, 1 Sep 2021 11:50:26 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: ff2bc3a8-9831-43ca-c9f4-08d96d3eb0ec X-MS-TrafficTypeDiagnostic: SN6PR03MB4224: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:7691; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:SN6PR03MB3871.namprd03.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(346002)(396003)(136003)(376002)(366004)(39860400002)(75432002)(8936002)(38100700002)(38350700002)(6486002)(4326008)(52116002)(5660300002)(86362001)(36756003)(956004)(2616005)(2906002)(66476007)(66556008)(54906003)(1076003)(83380400001)(186003)(316002)(6916009)(66946007)(6512007)(6506007)(8676002)(26005)(478600001)(6666004); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?q?WV64C+HMfuu2vUKTBT9rJNYtIyXL?= =?utf-8?q?iWEKt4d5Y4NObHR/zupI/CKXR9r4hHQOhe9QdgzQW1AGredXRcAVTxd3k/IB38ivx?= =?utf-8?q?Oa1BzVujWDDTLJWs6elSodylctpqX1FbxVKd3EJnbMBM7yuSqiRk+6s7W8WSgzniP?= =?utf-8?q?/nBpVK24LfLtuemLAsorJIvPatpFhSfKQCDP27ZoIV8rx2xb4kDYgckt2FkyhIRSe?= =?utf-8?q?NOn5jAUZeWbciKA2ZzPXWZ0TLscOEKebJJZTijdNQyyfQkZ6vWq+jgqHXii17ZkYj?= =?utf-8?q?43rZv+STeL8K8yGuRG9wNes6i5gNAhgtuEJXA3jdhrMkB8uqBCAWZUf1dcoHJkgC9?= =?utf-8?q?OzJM2C53ALat59Bu1IydLry+MZtjk/J11m0bJOBcAEqN/Ear1qOvc3pqcY9p4Nd3W?= =?utf-8?q?ueCONHwSa3xnAPx22bA600Aqjig4VK35Dr97aeQJ0q1x5iuHwuiotgwikN0DU9IvG?= =?utf-8?q?dsTM28vJqJa5vLjE3vPXlx96PpYpW16c00Xs3FWUwQrGLXzvqINhFbi+SoEZqD0FC?= =?utf-8?q?KJw4r87UblcjHML3TOpu3M6LYl8VdCA9lJ32dVZWRchgPymZmKwsZjRO9PisfiEpF?= =?utf-8?q?V7yQmpk1aLkiU7C4jiLIzFXIPZiwI94SlqDKfbSHvHKjFkFrc6DpUJZM9xnXOTLuS?= =?utf-8?q?Sx3ZNNo9S3CIa8dGwR91o6zCdwV/LZqqVFCtGvjdS6HQewb+OJAocMrGLUD1LutI3?= =?utf-8?q?SX7qPNmTo3VaS7hhUj71N9nWG/ScTU25l2MB/4/dJGxt9YNuJOhDPSm9aI6BATN/o?= =?utf-8?q?hMrc/1tonzLdEt7AXsunhjujXqZXrAmbvZHjIj/AYN5BwrLCMIZUkXkxLQ3sQvIMi?= =?utf-8?q?hmHwDbAoQlVq/otKGcbwVgx1CsXhFn0inZypES3YrPYs7c5px6jCh3R1MvHXHc3W5?= =?utf-8?q?GRmJijaC0CGtX4QqeBncbHpZscQsNIYBcetiCgpeP6chF12/uKxdX72tZ7qo80lKo?= =?utf-8?q?JkZgEFu5Wj/Iaa6x1jyV6+v7Xv7YxYvu7jdlxILF6ifPRO/hYMi7i76aOIfUptzRx?= =?utf-8?q?eprNFgREx3b0bGUFYGbUZ6ywsQ1/2/zQNHDV44H/eWLsBgINztaPqWeo4loubc6WO?= =?utf-8?q?rtWfFguCFjR+m8K3HJsqqscb8I9hncuvbPol4WynURbUXXdhh22UrjH3J87Pswt/k?= =?utf-8?q?rbKXVn1bslFlxvndTcYoFS1IJ3gIPETG5Zsy+Gz07elYQdgj52m/0GE/JGQCXCUQP?= =?utf-8?q?uL6c6GG68KIexAXAuHfeaiDplJ1OF7xy5nefUOqDd7y88cbhUXgnTP509OMI5ZoHa?= =?utf-8?q?PZr76arnHHHyLHkx?= X-OriginatorOrg: bu.edu X-MS-Exchange-CrossTenant-Network-Message-Id: ff2bc3a8-9831-43ca-c9f4-08d96d3eb0ec X-MS-Exchange-CrossTenant-AuthSource: SN6PR03MB3871.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Sep 2021 11:50:27.4873 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: d57d32cc-c121-488f-b07b-dfe705680c71 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: t0BfEQgzATjKv0LRoE+MC88QHamZzl9/npItXT5ysq9OKPzM2yVxvbS0m7FbmxPV X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR03MB4224 Received-SPF: pass client-ip=40.107.92.134; envelope-from=alxndr@bu.edu; helo=NAM10-BN7-obe.outbound.protection.outlook.com X-Spam_score_int: -8 X-Spam_score: -0.9 X-Spam_bar: / X-Spam_report: (-0.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HK_RANDOM_ENVFROM=0.238, HK_RANDOM_FROM=0.999, MSGID_FROM_MTA_HEADER=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: bonzini@redhat.com, peter.maydell@linaro.org, =?utf-8?q?Philippe_Mathieu?= =?utf-8?q?-Daud=C3=A9?= , Darren Kenny , Alexander Bulekov Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The code mistakenly relied on address_space_translate to store the length remaining until the next memory-region. We care about this because when there is RAM or sparse-memory neighboring on an MMIO region, we should only write up to the border, to prevent inadvertently invoking MMIO handlers within the DMA callback. However address_space_translate_internal only stores the length until the end of the MemoryRegion if memory_region_is_ram(mr). Otherwise the *len is left unmodified. This caused some false-positive issues, where the fuzzer found a way to perform a nested MMIO write through a DMA callback on an [address, length] that started within sparse memory and spanned some device MMIO regions. To fix this, write to sparse memory in small chunks of memory_access_size (similar to the underlying address_space_write code), which will prevent accidentally hitting MMIO handlers through large writes. Signed-off-by: Alexander Bulekov Reviewed-by: Darren Kenny Reviewed-by: Philippe Mathieu-Daudé --- tests/qtest/fuzz/generic_fuzz.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/tests/qtest/fuzz/generic_fuzz.c b/tests/qtest/fuzz/generic_fuzz.c index 6c67522717..0ea47298b7 100644 --- a/tests/qtest/fuzz/generic_fuzz.c +++ b/tests/qtest/fuzz/generic_fuzz.c @@ -240,10 +240,17 @@ void fuzz_dma_read_cb(size_t addr, size_t len, MemoryRegion *mr) addr, &addr1, &l, true, MEMTXATTRS_UNSPECIFIED); - if (!(memory_region_is_ram(mr1) || - memory_region_is_romd(mr1)) && mr1 != sparse_mem_mr) { + /* + * If mr1 isn't RAM, address_space_translate doesn't update l. Use + * memory_access_size to identify the number of bytes that it is safe + * to write without accidentally writing to another MemoryRegion. + */ + if (!memory_region_is_ram(mr1)) { l = memory_access_size(mr1, l, addr1); - } else { + } + if (memory_region_is_ram(mr1) || + memory_region_is_romd(mr1) || + mr1 == sparse_mem_mr) { /* ROM/RAM case */ if (qtest_log_enabled) { /*