From: Lu Baolu <baolu.lu@linux.intel.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Joerg Roedel <joro@8bytes.org>, Alex Williamson <alex.williamson@redhat.com>, Bjorn Helgaas <bhelgaas@google.com>, Jason Gunthorpe <jgg@nvidia.com>, Christoph Hellwig <hch@infradead.org>, Kevin Tian <kevin.tian@intel.com>, Ashok Raj <ashok.raj@intel.com> Cc: Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>, Dan Williams <dan.j.williams@intel.com>, rafael@kernel.org, Diana Craciun <diana.craciun@oss.nxp.com>, Cornelia Huck <cohuck@redhat.com>, Eric Auger <eric.auger@redhat.com>, Liu Yi L <yi.l.liu@intel.com>, Jacob jun Pan <jacob.jun.pan@intel.com>, Chaitanya Kulkarni <kch@nvidia.com>, Stuart Yoder <stuyoder@gmail.com>, Laurentiu Tudor <laurentiu.tudor@nxp.com>, Thierry Reding <thierry.reding@gmail.com>, David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>, Jonathan Hunter <jonathanh@nvidia.com>, Li Yang <leoyang.li@nxp.com>, Dmitry Osipenko <digetx@gmail.com>, iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu <baolu.lu@linux.intel.com> Subject: [PATCH v4 00/13] Fix BUG_ON in vfio_iommu_group_notifier() Date: Fri, 17 Dec 2021 14:36:55 +0800 [thread overview] Message-ID: <20211217063708.1740334-1-baolu.lu@linux.intel.com> (raw) Hi folks, The iommu group is the minimal isolation boundary for DMA. Devices in a group can access each other's MMIO registers via peer to peer DMA and also need share the same I/O address space. Once the I/O address space is assigned to user control it is no longer available to the dma_map* API, which effectively makes the DMA API non-working. Second, userspace can use DMA initiated by a device that it controls to access the MMIO spaces of other devices in the group. This allows userspace to indirectly attack any kernel owned device and it's driver. Therefore groups must either be entirely under kernel control or userspace control, never a mixture. Unfortunately some systems have problems with the granularity of groups and there are a couple of important exceptions: - pci_stub allows the admin to block driver binding on a device and make it permanently shared with userspace. Since PCI stub does not do DMA it is safe, however the admin must understand that using pci_stub allows userspace to attack whatever device it was bound it. - PCI bridges are sometimes included in groups. Typically PCI bridges do not use DMA, and generally do not have MMIO regions. Generally any device that does not have any MMIO registers is a possible candidate for an exception. Currently vfio adopts a workaround to detect violations of the above restrictions by monitoring the driver core BOUND event, and hardwiring the above exceptions. Since there is no way for vfio to reject driver binding at this point, BUG_ON() is triggered if a violation is captured (kernel driver BOUND event on a group which already has some devices assigned to userspace). Aside from the bad user experience this opens a way for root userspace to crash the kernel, even in high integrity configurations, by manipulating the module binding and triggering the BUG_ON. This series solves this problem by making the user/kernel ownership a core concept at the IOMMU layer. The driver core enforces kernel ownership while drivers are bound and violations now result in a error codes during probe, not BUG_ON failures. Patch partitions: [PATCH 1-4]: Detect DMA ownership conflicts during driver binding; [PATCH 5-8]: Add security context management for assigned devices; [PATCH 9-13]: Various cleanups. This is also part one of three initial series for IOMMUFD: * Move IOMMU Group security into the iommu layer - Generic IOMMUFD implementation - VFIO ability to consume IOMMUFD Change log: v1: initial post - https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/ v2: - https://lore.kernel.org/linux-iommu/20211128025051.355578-1-baolu.lu@linux.intel.com/ - Move kernel dma ownership auto-claiming from driver core to bus callback. [Greg/Christoph/Robin/Jason] https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/T/#m153706912b770682cb12e3c28f57e171aa1f9d0c - Code and interface refactoring for iommu_set/release_dma_owner() interfaces. [Jason] https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/T/#mea70ed8e4e3665aedf32a5a0a7db095bf680325e - [NEW]Add new iommu_attach/detach_device_shared() interfaces for multiple devices group. [Robin/Jason] https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/T/#mea70ed8e4e3665aedf32a5a0a7db095bf680325e - [NEW]Use iommu_attach/detach_device_shared() in drm/tegra drivers. - Refactoring and description refinement. v3: - https://lore.kernel.org/linux-iommu/20211206015903.88687-1-baolu.lu@linux.intel.com/ - Rename bus_type::dma_unconfigure to bus_type::dma_cleanup. [Greg] https://lore.kernel.org/linux-iommu/c3230ace-c878-39db-1663-2b752ff5384e@linux.intel.com/T/#m6711e041e47cb0cbe3964fad0a3466f5ae4b3b9b - Avoid _platform_dma_configure for platform_bus_type::dma_configure. [Greg] https://lore.kernel.org/linux-iommu/c3230ace-c878-39db-1663-2b752ff5384e@linux.intel.com/T/#m43fc46286611aa56a5c0eeaad99d539e5519f3f6 - Patch "0012-iommu-Add-iommu_at-de-tach_device_shared-for-mult.patch" and "0018-drm-tegra-Use-the-iommu-dma_owner-mechanism.patch" have been tested by Dmitry Osipenko <digetx@gmail.com>. v4: - Remove unnecessary tegra->domain chech in the tegra patch. (Jason) - Remove DMA_OWNER_NONE. (Joerg) - Change refcount to unsigned int. (Christoph) - Move mutex lock into group set_dma_owner functions. (Christoph) - Add kernel doc for iommu_attach/detach_domain_shared(). (Christoph) - Move dma auto-claim into driver core. (Jason/Christoph) This is based on next branch of linux-iommu tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git and also available on github: https://github.com/LuBaolu/intel-iommu/commits/iommu-dma-ownership-v4 Merry Christmas to you all! Best regards, baolu Jason Gunthorpe (2): vfio: Delete the unbound_list drm/tegra: Use the iommu dma_owner mechanism Lu Baolu (11): iommu: Add device dma ownership set/release interfaces driver core: Set DMA ownership during driver bind/unbind PCI: pci_stub: Suppress kernel DMA ownership auto-claiming PCI: portdrv: Suppress kernel DMA ownership auto-claiming iommu: Add security context management for assigned devices iommu: Expose group variants of dma ownership interfaces iommu: Add iommu_at[de]tach_device_shared() for multi-device groups vfio: Set DMA USER ownership for VFIO devices vfio: Remove use of vfio_group_viable() vfio: Remove iommu group notifier iommu: Remove iommu group changes notifier include/linux/device/driver.h | 2 + include/linux/iommu.h | 91 ++++++-- drivers/base/dd.c | 37 ++- drivers/gpu/drm/tegra/dc.c | 1 + drivers/gpu/drm/tegra/drm.c | 54 ++--- drivers/gpu/drm/tegra/gr2d.c | 1 + drivers/gpu/drm/tegra/gr3d.c | 1 + drivers/gpu/drm/tegra/vic.c | 3 +- drivers/iommu/iommu.c | 321 +++++++++++++++++++------- drivers/pci/pci-stub.c | 3 + drivers/pci/pcie/portdrv_pci.c | 5 +- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 1 + drivers/vfio/pci/vfio_pci.c | 3 + drivers/vfio/platform/vfio_amba.c | 1 + drivers/vfio/platform/vfio_platform.c | 1 + drivers/vfio/vfio.c | 248 ++------------------ 16 files changed, 406 insertions(+), 367 deletions(-) -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Lu Baolu <baolu.lu@linux.intel.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Joerg Roedel <joro@8bytes.org>, Alex Williamson <alex.williamson@redhat.com>, Bjorn Helgaas <bhelgaas@google.com>, Jason Gunthorpe <jgg@nvidia.com>, Christoph Hellwig <hch@infradead.org>, Kevin Tian <kevin.tian@intel.com>, Ashok Raj <ashok.raj@intel.com> Cc: kvm@vger.kernel.org, rafael@kernel.org, David Airlie <airlied@linux.ie>, linux-pci@vger.kernel.org, Thierry Reding <thierry.reding@gmail.com>, Diana Craciun <diana.craciun@oss.nxp.com>, Dmitry Osipenko <digetx@gmail.com>, Will Deacon <will@kernel.org>, Stuart Yoder <stuyoder@gmail.com>, Jonathan Hunter <jonathanh@nvidia.com>, Chaitanya Kulkarni <kch@nvidia.com>, Dan Williams <dan.j.williams@intel.com>, Cornelia Huck <cohuck@redhat.com>, linux-kernel@vger.kernel.org, Li Yang <leoyang.li@nxp.com>, iommu@lists.linux-foundation.org, Jacob jun Pan <jacob.jun.pan@intel.com>, Daniel Vetter <daniel@ffwll.ch>, Robin Murphy <robin.murphy@arm.com> Subject: [PATCH v4 00/13] Fix BUG_ON in vfio_iommu_group_notifier() Date: Fri, 17 Dec 2021 14:36:55 +0800 [thread overview] Message-ID: <20211217063708.1740334-1-baolu.lu@linux.intel.com> (raw) Hi folks, The iommu group is the minimal isolation boundary for DMA. Devices in a group can access each other's MMIO registers via peer to peer DMA and also need share the same I/O address space. Once the I/O address space is assigned to user control it is no longer available to the dma_map* API, which effectively makes the DMA API non-working. Second, userspace can use DMA initiated by a device that it controls to access the MMIO spaces of other devices in the group. This allows userspace to indirectly attack any kernel owned device and it's driver. Therefore groups must either be entirely under kernel control or userspace control, never a mixture. Unfortunately some systems have problems with the granularity of groups and there are a couple of important exceptions: - pci_stub allows the admin to block driver binding on a device and make it permanently shared with userspace. Since PCI stub does not do DMA it is safe, however the admin must understand that using pci_stub allows userspace to attack whatever device it was bound it. - PCI bridges are sometimes included in groups. Typically PCI bridges do not use DMA, and generally do not have MMIO regions. Generally any device that does not have any MMIO registers is a possible candidate for an exception. Currently vfio adopts a workaround to detect violations of the above restrictions by monitoring the driver core BOUND event, and hardwiring the above exceptions. Since there is no way for vfio to reject driver binding at this point, BUG_ON() is triggered if a violation is captured (kernel driver BOUND event on a group which already has some devices assigned to userspace). Aside from the bad user experience this opens a way for root userspace to crash the kernel, even in high integrity configurations, by manipulating the module binding and triggering the BUG_ON. This series solves this problem by making the user/kernel ownership a core concept at the IOMMU layer. The driver core enforces kernel ownership while drivers are bound and violations now result in a error codes during probe, not BUG_ON failures. Patch partitions: [PATCH 1-4]: Detect DMA ownership conflicts during driver binding; [PATCH 5-8]: Add security context management for assigned devices; [PATCH 9-13]: Various cleanups. This is also part one of three initial series for IOMMUFD: * Move IOMMU Group security into the iommu layer - Generic IOMMUFD implementation - VFIO ability to consume IOMMUFD Change log: v1: initial post - https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/ v2: - https://lore.kernel.org/linux-iommu/20211128025051.355578-1-baolu.lu@linux.intel.com/ - Move kernel dma ownership auto-claiming from driver core to bus callback. [Greg/Christoph/Robin/Jason] https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/T/#m153706912b770682cb12e3c28f57e171aa1f9d0c - Code and interface refactoring for iommu_set/release_dma_owner() interfaces. [Jason] https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/T/#mea70ed8e4e3665aedf32a5a0a7db095bf680325e - [NEW]Add new iommu_attach/detach_device_shared() interfaces for multiple devices group. [Robin/Jason] https://lore.kernel.org/linux-iommu/20211115020552.2378167-1-baolu.lu@linux.intel.com/T/#mea70ed8e4e3665aedf32a5a0a7db095bf680325e - [NEW]Use iommu_attach/detach_device_shared() in drm/tegra drivers. - Refactoring and description refinement. v3: - https://lore.kernel.org/linux-iommu/20211206015903.88687-1-baolu.lu@linux.intel.com/ - Rename bus_type::dma_unconfigure to bus_type::dma_cleanup. [Greg] https://lore.kernel.org/linux-iommu/c3230ace-c878-39db-1663-2b752ff5384e@linux.intel.com/T/#m6711e041e47cb0cbe3964fad0a3466f5ae4b3b9b - Avoid _platform_dma_configure for platform_bus_type::dma_configure. [Greg] https://lore.kernel.org/linux-iommu/c3230ace-c878-39db-1663-2b752ff5384e@linux.intel.com/T/#m43fc46286611aa56a5c0eeaad99d539e5519f3f6 - Patch "0012-iommu-Add-iommu_at-de-tach_device_shared-for-mult.patch" and "0018-drm-tegra-Use-the-iommu-dma_owner-mechanism.patch" have been tested by Dmitry Osipenko <digetx@gmail.com>. v4: - Remove unnecessary tegra->domain chech in the tegra patch. (Jason) - Remove DMA_OWNER_NONE. (Joerg) - Change refcount to unsigned int. (Christoph) - Move mutex lock into group set_dma_owner functions. (Christoph) - Add kernel doc for iommu_attach/detach_domain_shared(). (Christoph) - Move dma auto-claim into driver core. (Jason/Christoph) This is based on next branch of linux-iommu tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git and also available on github: https://github.com/LuBaolu/intel-iommu/commits/iommu-dma-ownership-v4 Merry Christmas to you all! Best regards, baolu Jason Gunthorpe (2): vfio: Delete the unbound_list drm/tegra: Use the iommu dma_owner mechanism Lu Baolu (11): iommu: Add device dma ownership set/release interfaces driver core: Set DMA ownership during driver bind/unbind PCI: pci_stub: Suppress kernel DMA ownership auto-claiming PCI: portdrv: Suppress kernel DMA ownership auto-claiming iommu: Add security context management for assigned devices iommu: Expose group variants of dma ownership interfaces iommu: Add iommu_at[de]tach_device_shared() for multi-device groups vfio: Set DMA USER ownership for VFIO devices vfio: Remove use of vfio_group_viable() vfio: Remove iommu group notifier iommu: Remove iommu group changes notifier include/linux/device/driver.h | 2 + include/linux/iommu.h | 91 ++++++-- drivers/base/dd.c | 37 ++- drivers/gpu/drm/tegra/dc.c | 1 + drivers/gpu/drm/tegra/drm.c | 54 ++--- drivers/gpu/drm/tegra/gr2d.c | 1 + drivers/gpu/drm/tegra/gr3d.c | 1 + drivers/gpu/drm/tegra/vic.c | 3 +- drivers/iommu/iommu.c | 321 +++++++++++++++++++------- drivers/pci/pci-stub.c | 3 + drivers/pci/pcie/portdrv_pci.c | 5 +- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 1 + drivers/vfio/pci/vfio_pci.c | 3 + drivers/vfio/platform/vfio_amba.c | 1 + drivers/vfio/platform/vfio_platform.c | 1 + drivers/vfio/vfio.c | 248 ++------------------ 16 files changed, 406 insertions(+), 367 deletions(-) -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next reply other threads:[~2021-12-17 6:37 UTC|newest] Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-17 6:36 Lu Baolu [this message] 2021-12-17 6:36 ` [PATCH v4 00/13] Fix BUG_ON in vfio_iommu_group_notifier() Lu Baolu 2021-12-17 6:36 ` [PATCH v4 01/13] iommu: Add device dma ownership set/release interfaces Lu Baolu 2021-12-17 6:36 ` Lu Baolu 2021-12-17 6:36 ` [PATCH v4 02/13] driver core: Set DMA ownership during driver bind/unbind Lu Baolu 2021-12-17 6:36 ` Lu Baolu 2021-12-22 12:47 ` Greg Kroah-Hartman 2021-12-22 12:47 ` Greg Kroah-Hartman 2021-12-22 17:52 ` Jason Gunthorpe 2021-12-22 17:52 ` Jason Gunthorpe via iommu 2021-12-23 2:08 ` Lu Baolu 2021-12-23 2:08 ` Lu Baolu 2021-12-23 3:02 ` Lu Baolu 2021-12-23 3:02 ` Lu Baolu 2021-12-23 7:13 ` Greg Kroah-Hartman 2021-12-23 7:13 ` Greg Kroah-Hartman 2021-12-23 7:23 ` Lu Baolu 2021-12-23 7:23 ` Lu Baolu 2021-12-31 0:36 ` Jason Gunthorpe 2021-12-31 0:36 ` Jason Gunthorpe via iommu 2021-12-17 6:36 ` [PATCH v4 03/13] PCI: pci_stub: Suppress kernel DMA ownership auto-claiming Lu Baolu 2021-12-17 6:36 ` Lu Baolu 2021-12-29 20:42 ` Bjorn Helgaas 2021-12-29 20:42 ` Bjorn Helgaas 2021-12-30 5:34 ` Lu Baolu 2021-12-30 5:34 ` Lu Baolu 2021-12-30 22:24 ` Bjorn Helgaas 2021-12-30 22:24 ` Bjorn Helgaas 2021-12-31 0:40 ` Jason Gunthorpe 2021-12-31 0:40 ` Jason Gunthorpe via iommu 2021-12-31 1:10 ` Lu Baolu 2021-12-31 1:10 ` Lu Baolu 2021-12-31 1:58 ` Lu Baolu 2021-12-31 1:58 ` Lu Baolu 2022-01-03 19:53 ` Jason Gunthorpe 2022-01-03 19:53 ` Jason Gunthorpe via iommu 2022-01-04 1:54 ` Lu Baolu 2022-01-04 1:54 ` Lu Baolu 2021-12-31 1:06 ` Lu Baolu 2021-12-31 1:06 ` Lu Baolu 2021-12-17 6:36 ` [PATCH v4 04/13] PCI: portdrv: " Lu Baolu 2021-12-17 6:36 ` Lu Baolu 2021-12-29 21:16 ` Bjorn Helgaas 2021-12-29 21:16 ` Bjorn Helgaas 2021-12-30 5:49 ` Lu Baolu 2021-12-30 5:49 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 05/13] iommu: Add security context management for assigned devices Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 06/13] iommu: Expose group variants of dma ownership interfaces Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 07/13] iommu: Add iommu_at[de]tach_device_shared() for multi-device groups Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-21 16:50 ` Robin Murphy 2021-12-21 16:50 ` Robin Murphy 2021-12-21 18:46 ` Jason Gunthorpe 2021-12-21 18:46 ` Jason Gunthorpe via iommu 2021-12-22 4:22 ` Lu Baolu 2021-12-22 4:22 ` Lu Baolu 2021-12-22 4:25 ` Lu Baolu 2021-12-22 4:25 ` Lu Baolu 2021-12-22 20:26 ` Robin Murphy 2021-12-22 20:26 ` Robin Murphy 2021-12-23 0:57 ` Jason Gunthorpe 2021-12-23 0:57 ` Jason Gunthorpe via iommu 2021-12-23 5:53 ` Lu Baolu 2021-12-23 5:53 ` Lu Baolu 2021-12-23 14:03 ` Jason Gunthorpe 2021-12-23 14:03 ` Jason Gunthorpe via iommu 2021-12-24 1:30 ` Lu Baolu 2021-12-24 1:30 ` Lu Baolu 2021-12-24 2:50 ` Jason Gunthorpe 2021-12-24 2:50 ` Jason Gunthorpe via iommu 2021-12-24 6:44 ` Lu Baolu 2021-12-24 6:44 ` Lu Baolu 2022-01-04 1:53 ` Lu Baolu 2022-01-04 1:53 ` Lu Baolu 2021-12-24 3:19 ` Lu Baolu 2021-12-24 3:19 ` Lu Baolu 2021-12-24 14:24 ` Jason Gunthorpe 2021-12-24 14:24 ` Jason Gunthorpe via iommu 2021-12-17 6:37 ` [PATCH v4 08/13] vfio: Set DMA USER ownership for VFIO devices Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 09/13] vfio: Remove use of vfio_group_viable() Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 10/13] vfio: Delete the unbound_list Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 11/13] vfio: Remove iommu group notifier Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 12/13] iommu: Remove iommu group changes notifier Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2021-12-17 6:37 ` [PATCH v4 13/13] drm/tegra: Use the iommu dma_owner mechanism Lu Baolu 2021-12-17 6:37 ` Lu Baolu 2022-01-04 5:23 ` [PATCH v4 00/13] Fix BUG_ON in vfio_iommu_group_notifier() Lu Baolu 2022-01-04 5:23 ` Lu Baolu
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