From patchwork Thu May 27 12:58:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claire Chang X-Patchwork-Id: 1484579 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=N/RAF9cN; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4FrSYv4wZRz9sT6 for ; Thu, 27 May 2021 22:58:59 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235734AbhE0NAa (ORCPT ); Thu, 27 May 2021 09:00:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235676AbhE0NA3 (ORCPT ); Thu, 27 May 2021 09:00:29 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DECE9C061574 for ; Thu, 27 May 2021 05:58:55 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id q6so393800pjj.2 for ; Thu, 27 May 2021 05:58:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=kA+3MDeoUW6g7BAIQhmMZU6jpRRh7iFmQAMuxd9InLo=; b=N/RAF9cNvTcRd3iZmeYm87pVaO7FRy7mf9/WxIyCft3/KEf6OSpP1KzfVNdxCB6y/v f9rFlfhM52r7diCBgVLUZz2KQytMc21laqchIO1r5VInxr59Sd+7C4c0jiL2C5LzFLDG Gn+MKH5XFhuZrfNlpbnQvXijnbOOZUN/Rm2WA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=kA+3MDeoUW6g7BAIQhmMZU6jpRRh7iFmQAMuxd9InLo=; b=Tpz9csgqsTqWz6JbqLmRo8tVaUAO4FC4ufnFRZ692P5MrSEVeS69hQluVAJ7Ypz9bz NC2hjyw45PmnVV0AixjeezcAD0NIBQHnJOtucQOueTwWbreofcrM6A8TdWOEGv9NlBTQ ARLdP/4XRp2n/Xwrhz+0mI4CqHoEu4fQPgKqXMypIbPPB0ihNyqNUoYoGgM+pKi+vfE5 g6P2AseAwzB+QMjarbNCC18/lS9CtLWtmu25MMob2OYF7GJHzqAXBC/uvl3xf7Hqy7h6 Pu7SmmHvagafEkijfQa34si2Pm1ENCSujaEasQMTe6gwOdI4ETia9bIezuas6fL1jSpw K6ig== X-Gm-Message-State: AOAM5327BmdEDzUtNV90tPRm8Lh7mcqL+s2hcaAORj6lr1887svhUQFx GlfXrEPiEmTyufeMNZs3bUCjug== X-Google-Smtp-Source: ABdhPJxa0KAbUWt2GVQAhxJJasbt6KcrMvbewz9fOfHqfZGpT+rFwlvdT6CpO+Xk/o30NYlBhsWhJg== X-Received: by 2002:a17:90a:b22:: with SMTP id 31mr9588913pjq.179.1622120335442; Thu, 27 May 2021 05:58:55 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:a93:378d:9a9e:3b70]) by smtp.gmail.com with UTF8SMTPSA id e7sm2084005pfl.171.2021.05.27.05.58.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 May 2021 05:58:54 -0700 (PDT) From: Claire Chang To: Rob Herring , mpe@ellerman.id.au, Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Cc: benh@kernel.crashing.org, paulus@samba.org, "list@263.net:IOMMU DRIVERS" , sstabellini@kernel.org, Robin Murphy , grant.likely@arm.com, xypron.glpk@gmx.de, Thierry Reding , mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org, Greg KH , Saravana Kannan , "Rafael J . Wysocki" , heikki.krogerus@linux.intel.com, Andy Shevchenko , Randy Dunlap , Dan Williams , Bartosz Golaszewski , linux-devicetree , lkml , linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org, Nicolas Boichat , Jim Quinlan , tfiga@chromium.org, bskeggs@redhat.com, bhelgaas@google.com, chris@chris-wilson.co.uk, tientzu@chromium.org, daniel@ffwll.ch, airlied@linux.ie, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, jxgao@google.com, joonas.lahtinen@linux.intel.com, linux-pci@vger.kernel.org, maarten.lankhorst@linux.intel.com, matthew.auld@intel.com, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com Subject: [PATCH v8 00/15] Restricted DMA Date: Thu, 27 May 2021 20:58:30 +0800 Message-Id: <20210527125845.1852284-1-tientzu@chromium.org> X-Mailer: git-send-email 2.31.1.818.g46aad6cb9e-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This series implements mitigations for lack of DMA access control on systems without an IOMMU, which could result in the DMA accessing the system memory at unexpected times and/or unexpected addresses, possibly leading to data leakage or corruption. For example, we plan to use the PCI-e bus for Wi-Fi and that PCI-e bus is not behind an IOMMU. As PCI-e, by design, gives the device full access to system memory, a vulnerability in the Wi-Fi firmware could easily escalate to a full system exploit (remote wifi exploits: [1a], [1b] that shows a full chain of exploits; [2], [3]). To mitigate the security concerns, we introduce restricted DMA. Restricted DMA utilizes the existing swiotlb to bounce streaming DMA in and out of a specially allocated region and does memory allocation from the same region. The feature on its own provides a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to restrict the DMA to a predefined memory region (this is usually done at firmware level, e.g. MPU in ATF on some ARM platforms [4]). [1a] https://googleprojectzero.blogspot.com/2017/04/over-air-exploiting-broadcoms-wi-fi_4.html [1b] https://googleprojectzero.blogspot.com/2017/04/over-air-exploiting-broadcoms-wi-fi_11.html [2] https://blade.tencent.com/en/advisories/qualpwn/ [3] https://www.bleepingcomputer.com/news/security/vulnerabilities-found-in-highly-popular-firmware-for-wifi-chips/ [4] https://github.com/ARM-software/arm-trusted-firmware/blob/master/plat/mediatek/mt8183/drivers/emi_mpu/emi_mpu.c#L132 v8: - Fix reserved-memory.txt and add the reg property in example. - Fix sizeof for of_property_count_elems_of_size in drivers/of/address.c#of_dma_set_restricted_buffer. - Apply Will's suggestion to try the OF node having DMA configuration in drivers/of/address.c#of_dma_set_restricted_buffer. - Fix typo in the comment of drivers/of/address.c#of_dma_set_restricted_buffer. - Add error message for PageHighMem in kernel/dma/swiotlb.c#rmem_swiotlb_device_init and move it to rmem_swiotlb_setup. - Fix the message string in rmem_swiotlb_setup. v7: Fix debugfs, PageHighMem and comment style in rmem_swiotlb_device_init https://lore.kernel.org/patchwork/cover/1431031/ v6: Address the comments in v5 https://lore.kernel.org/patchwork/cover/1423201/ v5: Rebase on latest linux-next https://lore.kernel.org/patchwork/cover/1416899/ v4: - Fix spinlock bad magic - Use rmem->name for debugfs entry - Address the comments in v3 https://lore.kernel.org/patchwork/cover/1378113/ v3: Using only one reserved memory region for both streaming DMA and memory allocation. https://lore.kernel.org/patchwork/cover/1360992/ v2: Building on top of swiotlb. https://lore.kernel.org/patchwork/cover/1280705/ v1: Using dma_map_ops. https://lore.kernel.org/patchwork/cover/1271660/ Claire Chang (15): swiotlb: Refactor swiotlb init functions swiotlb: Refactor swiotlb_create_debugfs swiotlb: Add DMA_RESTRICTED_POOL swiotlb: Add restricted DMA pool initialization swiotlb: Add a new get_io_tlb_mem getter swiotlb: Update is_swiotlb_buffer to add a struct device argument swiotlb: Update is_swiotlb_active to add a struct device argument swiotlb: Bounce data from/to restricted DMA pool if available swiotlb: Move alloc_size to find_slots swiotlb: Refactor swiotlb_tbl_unmap_single dma-direct: Add a new wrapper __dma_direct_free_pages() swiotlb: Add restricted DMA alloc/free support. dma-direct: Allocate memory from restricted DMA pool if available dt-bindings: of: Add restricted DMA pool of: Add plumbing for restricted DMA pool .../reserved-memory/reserved-memory.txt | 36 ++- drivers/gpu/drm/i915/gem/i915_gem_internal.c | 2 +- drivers/gpu/drm/nouveau/nouveau_ttm.c | 2 +- drivers/iommu/dma-iommu.c | 12 +- drivers/of/address.c | 25 ++ drivers/of/device.c | 3 + drivers/of/of_private.h | 5 + drivers/pci/xen-pcifront.c | 2 +- drivers/xen/swiotlb-xen.c | 2 +- include/linux/device.h | 4 + include/linux/swiotlb.h | 41 ++- kernel/dma/Kconfig | 14 + kernel/dma/direct.c | 63 +++-- kernel/dma/direct.h | 9 +- kernel/dma/swiotlb.c | 242 +++++++++++++----- 15 files changed, 362 insertions(+), 100 deletions(-) Tested-by: Will Deacon