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* [PATCH v5 00/16] Restricted DMA
@ 2021-04-22  8:14 Claire Chang
  2021-04-22  8:14 ` [PATCH v5 01/16] swiotlb: Fix the type of index Claire Chang
                   ` (16 more replies)
  0 siblings, 17 replies; 29+ messages in thread
From: Claire Chang @ 2021-04-22  8:14 UTC (permalink / raw)
  To: Joerg Roedel, Will Deacon, Frank Rowand, Konrad Rzeszutek Wilk,
	boris.ostrovsky, jgross, Christoph Hellwig, Marek Szyprowski
  Cc: benh, paulus, list@263.net:IOMMU DRIVERS, sstabellini,
	Robin Murphy, grant.likely, xypron.glpk, Thierry Reding, mingo,
	bauerman, peterz, Greg KH, Saravana Kannan, Rafael J . Wysocki,
	heikki.krogerus, Andy Shevchenko, Randy Dunlap, Dan Williams,
	Bartosz Golaszewski, linux-devicetree, lkml, linuxppc-dev,
	xen-devel, Nicolas Boichat, Jim Quinlan, tfiga, bskeggs,
	bhelgaas, chris, tientzu, daniel, airlied, dri-devel, intel-gfx,
	jani.nikula, jxgao, joonas.lahtinen, linux-pci,
	maarten.lankhorst, matthew.auld, nouveau, rodrigo.vivi,
	thomas.hellstrom

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

v5:
  Rebase on latest linux-next

v4:
  - Fix spinlock bad magic
  - Use rmem->name for debugfs entry
  - Address the comments in v3

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 (16):
  swiotlb: Fix the type of index
  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       |  24 ++
 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                           |  57 +++--
 kernel/dma/direct.h                           |   9 +-
 kernel/dma/swiotlb.c                          | 242 +++++++++++++-----
 15 files changed, 347 insertions(+), 97 deletions(-)

-- 
2.31.1.368.gbe11c130af-goog


^ permalink raw reply	[flat|nested] 29+ messages in thread

end of thread, other threads:[~2021-05-10  9:54 UTC | newest]

Thread overview: 29+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-22  8:14 [PATCH v5 00/16] Restricted DMA Claire Chang
2021-04-22  8:14 ` [PATCH v5 01/16] swiotlb: Fix the type of index Claire Chang
2021-04-23  7:11   ` Christoph Hellwig
2021-04-22  8:14 ` [PATCH v5 02/16] swiotlb: Refactor swiotlb init functions Claire Chang
2021-04-22  8:14 ` [PATCH v5 03/16] swiotlb: Refactor swiotlb_create_debugfs Claire Chang
2021-04-22  8:14 ` [PATCH v5 04/16] swiotlb: Add DMA_RESTRICTED_POOL Claire Chang
2021-04-22  8:14 ` [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization Claire Chang
2021-04-23 11:34   ` Steven Price
2021-04-26 16:37     ` Claire Chang
2021-04-28  9:50       ` Steven Price
2021-04-22  8:14 ` [PATCH v5 06/16] swiotlb: Add a new get_io_tlb_mem getter Claire Chang
2021-04-22  8:14 ` [PATCH v5 07/16] swiotlb: Update is_swiotlb_buffer to add a struct device argument Claire Chang
2021-04-22  8:15 ` [PATCH v5 08/16] swiotlb: Update is_swiotlb_active " Claire Chang
2021-04-23 13:31   ` Robin Murphy
2021-04-26 16:37     ` Claire Chang
2021-04-22  8:15 ` [PATCH v5 09/16] swiotlb: Bounce data from/to restricted DMA pool if available Claire Chang
2021-04-22  8:15 ` [PATCH v5 10/16] swiotlb: Move alloc_size to find_slots Claire Chang
2021-04-22  8:15 ` [PATCH v5 11/16] swiotlb: Refactor swiotlb_tbl_unmap_single Claire Chang
2021-04-22  8:15 ` [PATCH v5 12/16] dma-direct: Add a new wrapper __dma_direct_free_pages() Claire Chang
2021-04-22  8:15 ` [PATCH v5 13/16] swiotlb: Add restricted DMA alloc/free support Claire Chang
2021-04-22  8:15 ` [PATCH v5 14/16] dma-direct: Allocate memory from restricted DMA pool if available Claire Chang
2021-04-23 13:46   ` Robin Murphy
2021-05-03 14:26     ` Claire Chang
2021-04-22  8:15 ` [PATCH v5 15/16] dt-bindings: of: Add restricted DMA pool Claire Chang
2021-04-22  8:15 ` [PATCH v5 16/16] of: Add plumbing for " Claire Chang
2021-04-23  2:52   ` Claire Chang
2021-04-23 13:35   ` Robin Murphy
2021-04-26 16:38     ` Claire Chang
2021-05-10  9:53 ` [PATCH v5 00/16] Restricted DMA Claire Chang

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