{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80576",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80576"
  ],
  "published": "2026-08-26T14:37:59Z",
  "summary": "drm/amdgpu: reject oversized IBs with per-ring packet limits",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: reject oversized IBs with per-ring packet limits\n\nOn GFX rings, amdgpu_cs_p2_ib() passed user-supplied ib_bytes through\nto ib->length_dw without a limit, while ring_emit_ib() encodes length\ninto packet fields. Oversized values can corrupt adjacent control bits\nand destabilize command submission.\n\nAdd a per-ring IB packet size limit helper and reject command\nsubmissions exceeding the corresponding dword limit before IB\nallocation. Use the documented 20-bit limit for GFX/compute/SDMA/VPE,\nand apply the MM fallback limit for other ring types.\n\n(cherry picked from commit 7f48fa2cf62e3fa6c9c3870aa74988f773247e52)",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80576"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6e164ba1057175fb8a370d8e05cbff5c57eac0c8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1474f3970d1afd303e12ff14d06808eabb371576"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/07fe270ec07c138a70afe7a81e115a85c35c545c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fd37f9dd5b5ab70a46fa7bc76623c0528d602b27"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-27T05:18:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The bug is reached only through the AMDGPU_CS DRM ioctl on a local /dev/dri/renderD* render node; amdgpu_cs_p2_ib() takes user-supplied ib_bytes from command-submission chunks during local GPU job setup, with no network, adjacent-radio, or physical-access path to this code.\nAC:L - An attacker fully controls ib_bytes, ring selection, and backing BO mappings in each submit; triggering the flaw only requires one crafted IB chunk with length_dw above the hardware 20-bit packet limit (e.g., >0xFFFFF dwords), with no race or victim-dependent timing.\nPR:L - AMDGPU_CS is registered with DRM_AUTH|DRM_RENDER_ALLOW, so any authenticated render-client process with standard local access to /dev/dri/renderD* (typical render/video group on desktops, gaming PCs, and cloud GPU VMs) can reach amdgpu_cs_ioctl() without real root or init-namespace capabilities.\nUI:N - Exploitation is entirely self-contained in the attacker's own DRM client (open render node, allocate/map buffers, submit CS); no separate victim action such as opening a file, mounting a filesystem, or clicking a link is required.\nS:C - On GFX/compute rings, ring_emit_ib() ORs ib->length_dw into the INDIRECT_BUFFER control dword alongside VMID and preempt/valid bits; oversized values spill into those fields, so the GPU can execute IBs under an unintended VMID and perform DMA outside the attacker's GPU virtual address space, crossing per-client GPU/IOMMU isolation (e.g., multi-tenant cloud GPU).\nC:H - Corrupted VMID and adjacent control bits in the INDIRECT_BUFFER packet can redirect GPU fetches/execution into another client's GPU-mapped memory, providing a cross-context read primitive beyond the attacker's own BO mappings, not merely a benign driver error return.\nI:H - The same control-dword overflow can alter VALID/PREEMPT/VMID encoding so the GPU performs writes and command execution in an unintended address space, yielding cross-context memory corruption and a plausible path to arbitrary GPU-visible memory modification or further kernel compromise.\nA:H - Oversized IB lengths also destabilize command submission and can hang or reset GFX/SDMA rings (as noted in the fix and related IGT oversize-packet tests), denying GPU/display availability until driver reset or reboot on affected AMD systems."
    }
  }
}