From 0b307461d22a7bfa85d4ec87b80a0e5205fc3cd6 Mon Sep 17 00:00:00 2001 From: Arthur Hanson Rasmusson Date: Wed, 21 Oct 2026 03:29:12 -0400 Subject: docs: GPUBreach-class audit and threat model for the host write paths Audit of every host-side write whose target derives from guest data, against the GPUBreach (IEEE S&P 2026) chain: GPU PTE corruption -> arbitrary device read/write -> driver bugs -> CPU root. Findings: the host is structurally off that path (guest GPU page tables host-emulated, physical GPU PTEs host-owned, every write aperture-bounded by vfio_dma_rw to guest RAM or the vidmem shadow, no guest DMA to host buffers), and the remaining wrong-but-valid write class is bounded by the per-page resolution + refusal guards (FILL-TRUNC, FILL-PT-REFUSED, LOWFILL-REFUSED, GRFILL-DROP, stalled-VA demand, sema_copy_dst_pin_guard, DST-DIVERGE). Documents residual risks, what is not claimed (no isolation or side-channel claim; physical Rowhammer is out of scope), and three follow-ups. --- docs/README.md | 1 + 1 file changed, 1 insertion(+) (limited to 'docs/README.md') diff --git a/docs/README.md b/docs/README.md index 13f0ae5..27e04e9 100644 --- a/docs/README.md +++ b/docs/README.md @@ -183,6 +183,7 @@ Read in order if you are new. Jump directly if you know what you need. | 23 | [GSP in a RISC-V VM (risc-v-gsp-rm-debugger, experimental)](05-operations/03-risc-v-gsp-rm-vm.md) — implemented, documented and tested ([audit](../debug/risc-v-gsp-rm-vm/docs/27-TOOL-AUDIT.md); [value demos](../debug/risc-v-gsp-rm-vm/docs/25-VALUE-VALIDATION.md)) | developers, analysts | 15 min | | 24 | [risc-v-gsp-rm-debugger user guide (experimental)](05-operations/04-risc-v-gsp-rm-debugger-user-guide.md) — implemented, documented and tested ([audit](../debug/risc-v-gsp-rm-vm/docs/27-TOOL-AUDIT.md); [value demos](../debug/risc-v-gsp-rm-vm/docs/25-VALUE-VALIDATION.md)) | developers, analysts | 15 min | | 25 | [Defensive Operations Runbook](RUNBOOK.md) | maintainers, operators | 20 min | +| 25a | [GPUBreach-class audit and threat model](05-operations/05-gpubreach-audit.md) | developers, auditors | 15 min | | 26 | [Engineering operations](eng-ops.md) — tool admission and workflows (Part I) plus live physical-backend operations (Part II) | maintainers, developers | 20 min | | 27 | [Hardware and software matrix](06-portability/hardware-software-matrix.md) | developers, integrators | 20 min | | 28 | [Developer onboarding and standards](07-developers/onboarding-and-standards.md) | contributors | 20 min | -- cgit v1.2.3