linux-kernel - Re: [PATCH 1/1] iommu/sva: Invalidate KVA range on kernel TLB flush

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250709162724.GE1599700@nvidia.com>
Date: Wed, 9 Jul 2025 13:27:24 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Jacob Pan <jacob.pan@...ux.microsoft.com>
Cc: Lu Baolu <baolu.lu@...ux.intel.com>, Joerg Roedel <joro@...tes.org>,
	Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
	Kevin Tian <kevin.tian@...el.com>, Jann Horn <jannh@...gle.com>,
	Vasant Hegde <vasant.hegde@....com>,
	Dave Hansen <dave.hansen@...el.com>,
	Alistair Popple <apopple@...dia.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Uladzislau Rezki <urezki@...il.com>,
	Jean-Philippe Brucker <jean-philippe@...aro.org>,
	Andy Lutomirski <luto@...nel.org>, iommu@...ts.linux.dev,
	security@...nel.org, linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Subject: Re: [PATCH 1/1] iommu/sva: Invalidate KVA range on kernel TLB flush

On Wed, Jul 09, 2025 at 08:51:58AM -0700, Jacob Pan wrote:
> > In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU
> > hardware shares and walks the CPU's page tables. Architectures like
> > x86 share static kernel address mappings across all user page tables,
> > allowing the IOMMU to access the kernel portion of these tables.

> Is there a use case where a SVA user can access kernel memory in the
> first place?

No. It should be fully blocked.

Jason