{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-46215",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-46215"
  ],
  "published": "2026-05-28T09:40:54Z",
  "summary": "drm: Set old handle to NULL before prime swap in change_handle",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm: Set old handle to NULL before prime swap in change_handle\n\nThere was a potential race condition in change_handle. The ioctl\nbriefly had a single object with two idr entries; a concurrent\ngem_close could delete the object and remove one of the handles\nwhile leaving the other one dangling, which could subsequently\nbe dereferenced for a use-after-free.\n\nTo fix this, do the same dance that gem_close itself does.\n(f6cd7daecff5 drm: Release driver references to handle before making it available again)\nFirst idr_replace the old handle to NULL. Later, if the prime\noperations are successful, actually close it.\n\ncreate_tail required a similar dance to avoid a similar problem.\n(bd46cece51a3 drm/gem: Fix race in drm_gem_handle_create_tail())\nIt idr_allocs the new handle with NULL, then swaps in the correct\nobject later to avoid races. We don't need to do that here, since\nthe only operations that could race are drm_prime, and\nchange_handle holds the prime lock for the entire duration.\n\nv2: cleanups of error paths",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.18.29-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-2712",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v6",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v7",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v8",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.29-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.18.29-1+rpt1": {
            "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc",
            "upstream_version": "6.18.29",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.32"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-46215"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/672464dd53231509c9c771110798c56d4660e19e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/61bd96d3e5472c253f9c1ab77608f0c8aaa9d025"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5e28b7b94408897e41c63477aabc9e1db439bc8c"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The bug is reached only via the DRM_IOCTL_GEM_CHANGE_HANDLE ioctl on a local DRM device node (/dev/dri/renderD* or card*); there is no network or remote path to this code.\nAC:L - This is a race condition where the attacker controls both racing threads (one issuing GEM_CHANGE_HANDLE, another GEM_CLOSE on the same fd) and can retry the ioctls indefinitely, so the window is reliably winnable.\nPR:L - The ioctl is flagged DRM_RENDER_ALLOW with no DRM_AUTH/DRM_MASTER/DRM_ROOT_ONLY and no capability check, so any unprivileged local user with access to a DRM render node (standard on desktops/Android/kiosks) can trigger it.\nUI:N - The attacker drives the entire exploit through its own ioctls; no action by another user or victim is required.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security authority; it does not cross a VM/hypervisor or IOMMU boundary.\nC:H - A use-after-free on a heap-allocated drm_gem_object lets the attacker reclaim the freed slot with controlled data and read back object contents/pointers, enabling kernel memory disclosure.\nI:H - The dangling idr entry is dereferenced (kref_get write, plus obj->funcs->* calls), and a reclaimed UAF object gives heap-spray-based arbitrary write and control-flow hijacking primitives.\nA:H - Dereferencing the freed/dangling GEM object reliably causes kernel oops/panic, a full denial of service."
    }
  }
}