Messages in this thread | | | Date | Mon, 21 Feb 2022 11:38:17 +0800 | Subject | Re: [PATCH v6 00/11] Fix BUG_ON in vfio_iommu_group_notifier() | From | Lu Baolu <> |
| |
On 2/18/22 11:51 PM, Jason Gunthorpe wrote: > On Fri, Feb 18, 2022 at 08:55:10AM +0800, Lu Baolu wrote: >> 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. > This series has changed quite a lot since v1 - but I couldn't spot > anything wrong with this. It is a small incremental step and I think > it is fine now, so > > Reviewed-by: Jason Gunthorpe<jgg@nvidia.com> > > I hope you continue to work on the "Scrap iommu_attach/detach_group() > interfaces" series and try to minimize all the special places testing > against the default domain
Sure.
Best regards, baolu
| |