{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.12-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  iommu/amd: Remove latent out-of-bounds access in IOMMU debugfs  In iommu_mmio_write() and iommu_capability_write(), the variables dbg_mmio_offset and dbg_cap_offset are declared as int. However, they are populated using kstrtou32_from_user(). If a user provides a sufficiently large value, it can become a negative integer.  Prior to this patch, the AMD IOMMU debugfs implementation was already protected by different mechanisms.  1. #define OFS_IN_SZ 8 ensures the user string \u003c= 8 bytes, so    e.g. 0xffffffff isn't a valid input.    if (cnt \u003e OFS_IN_SZ)      return -EINVAL;  2. Implicit type promotion in iommu_mmio_write(), dbg_mmio_offset is int    and iommu-\u003emmio_phys_end is u64    if (dbg_mmio_offset \u003e iommu-\u003emmio_phys_end - sizeof(u64))       return -EINVAL;  3. The show handlers would currently catch the negative number and    refuse to perform the read.  Replace kstrtou32_from_user() with kstrtos32_from_user() to parse the input, and check for negative values to explicitly prevent out-of-bounds memory accesses directly in iommu_mmio_write() and iommu_capability_write().",
  "id": "DEBIAN-CVE-2026-64186",
  "modified": "2026-09-14T16:47:46.820886277Z",
  "published": "2026-07-19T16:18:01.037Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-64186"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-64186"
  ]
}