Messages in this thread | | | Date | Tue, 31 May 2022 12:59:04 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 01/12] iommu/vt-d: Use iommu_get_domain_for_dev() in debugfs |
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On Tue, May 31, 2022 at 02:52:28PM +0100, Robin Murphy wrote:
> > + break; > > + pgtable_walk_level(m, phys_to_virt(phys_addr), > > Also, obligatory reminder that pfn_valid() only means that pfn_to_page() > gets you a valid struct page. Whether that page is direct-mapped kernel > memory or not is a different matter.
Even though this is debugfs, if the operation is sketchy like that and can theortically crash the kernel the driver should test capabilities, CAP_SYS_RAWIO or something may be appropriate. I don't think we have a better cap for 'userspace may crash the kernel'
Jason
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