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drm/virtio: use the DMA API for resource backing on Xen

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

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
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Publisher date
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