drm/virtio: use the DMA API for resource backing on Xen
In the Linux kernel, the following vulnerability has been resolved: drm/virtio: use the DMA API for resource backing on Xen On a Xen PV domain page addresses bear no relation to the real machine addresses the host would have to use to reach it. virtio_ring.c handles this correctly, vring_use_map_api() returns true for any xen_domain() regardless of VIRTIO_F_ACCESS_PLATFORM. virtio-gpu makes the same decision independently, but its copy looks only at the feature bit: bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev); QEMU does not set iommu_platform on virtio-vga by default, so VIRTIO_F_ACCESS_PLATFORM is not negotiated, use_dma_api is false, and virtio_gpu_object_shmem_init() describes the framebuffer's backing pages to the host with sg_phys(). Those are guest-physical addresses. In a PV domain they resolve, on the host side, to pages belonging to some other domain, so the host scans out unrelated memory. Move the decision into virtio_gpu_use_dma_api() and give it the xen_domain() check, like vring_use_map_api() has. This additionally enables the dma_sync_sgtable_for_device() calls in virtgpu_vq.c, which are required for correctness whenever swiotlb is in play. Reproduced with a Xen 4.21 PV dom0 nested inside QEMU 8.2 with virtio-vga, on both a distro 6.8 kernel and 6.18 LTS. A PVH dom0 works fine and doesn't need this fix because it is identity-mapped, only PV dom0s are affected.
CVE-2026-98156
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98156
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "a3b815f09bb846255c458c181b8a5b1cc66891b4",
"lessThan": "32e999ccf5f6453b3b4df8264ff1b03c6720292f",
"versionType": "git"
},
{
"status": "affected",
"version": "a3b815f09bb846255c458c181b8a5b1cc66891b4",
"lessThan": "3f130cc6826fabf50e01fe8e4ff3ed1fcae50d36",
"versionType": "git"
},
{
"status": "affected",
"version": "a3b815f09bb846255c458c181b8a5b1cc66891b4",
"lessThan": "93c557e947ef0040004b1ac6a1c1265d79a957e1",
"versionType": "git"
},
{
"status": "affected",
"version": "a3b815f09bb846255c458c181b8a5b1cc66891b4",
"lessThan": "455184dbe9652d01470d3c5cf5edd09a7a673a99",
"versionType": "git"
},
{
"status": "affected",
"version": "a3b815f09bb846255c458c181b8a5b1cc66891b4",
"lessThan": "6a736d2f9d0c6e6217fe7532bc4c50ceca71db78",
"versionType": "git"
}
],
"programFiles": [
"drivers/gpu/drm/virtio/virtgpu_drv.h",
"drivers/gpu/drm/virtio/virtgpu_object.c",
"drivers/gpu/drm/virtio/virtgpu_vq.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/gpu/drm/virtio/virtgpu_drv.h",
"drivers/gpu/drm/virtio/virtgpu_object.c",
"drivers/gpu/drm/virtio/virtgpu_vq.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98156
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #48863 · Revision 1
- Added to Heist Feed
- Publisher date