drm/nouveau/dmem: fix mismatched DMA unmap size for large folios (CVE-2026-89804) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89804

drm/nouveau/dmem: fix mismatched DMA unmap size for large folios

Answer in brief

CVE-2026-89804 records a Unknown severity vulnerability in drm/nouveau/dmem: fix mismatched DMA unmap size for large folios. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 16, 2026Updated Sep 16, 2026Source checked Sep 16, 2026First seen by HOL Sep 16, 2026Material review Sep 16, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=c3228747107705d47c7e9a03598a434a0380cb73 <4deb29b9d33bfdb3de4d2d9944947ecf77221e42 \|\| >=c3228747107705d47c7e9a03598a434a0380cb73 <caa1bc2a0a6ca19dcb90bbf88208b0fe2decd66f	4deb29b9d33bfdb3de4d2d9944947ecf77221e42, caa1bc2a0a6ca19dcb90bbf88208b0fe2decd66f
Linux/Linuxgeneric	6.19	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 4deb29b9d33bfdb3de4d2d9944947ecf77221e42 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 16, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau/dmem: fix mismatched DMA unmap size for large folios Device-private THP migration maps migration buffers with page_size() and records that length in dma_info->size. For a compound folio page_size() is PAGE_SIZE << order, but two teardown sites still pass a literal PAGE_SIZE to dma_unmap_page(): - nouveau_dmem_migrate_to_ram() on the success path, and - nouveau_dmem_migrate_copy_one() on the copy-error path. For an order > 0 folio this unmaps less than was mapped, leaking the remainder of the IOMMU/IOVA mapping. The other unmap sites, in nouveau_dmem_migrate_chunk() and nouveau_dmem_evict_chunk(), already use the saved size; use it here too.

Quoted source text, attributed separately from HOL analysis.