{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7b09f5af01ede480cbe7abcb281cf17550a46ff5"
            },
            {
              "fixed": "ab275a23b4d9f04ca6c2f5f6a3246194e045a761"
            },
            {
              "fixed": "55e18311c705cceef6c34d522ea387b1f0069bab"
            },
            {
              "fixed": "2677f97a67fdbc62a82ce1faa67791f54451d36f"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.18.51"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93237.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Add DIRECT_MAP_PHYSMEM_END definition\n\nget_free_mem_region() and mhp_get_pluggable_range() bound their search\nto DIRECT_MAP_PHYSMEM_END. LoongArch does not define it, so the fallback\nin include/linux/mm.h applies: under CONFIG_SPARSEMEM_VMEMMAP it is\n(1ULL \u003c\u003c MAX_PHYSMEM_BITS) - 1, a compile-time constant that does not\nadapt to the CPU's physical address space bits (cpu_pabits, probed from\nCPUCFG1).\n\nThe vmemmap window only covers physical space below 2^(cpu_pabits+1)\n(i.e. VMEMMAP_SIZE), so on CPUs with fewer physical address bits than\nMAX_PHYSMEM_BITS the fallback allows get_free_mem_region() to return\na ZONE_DEVICE region outside the vmemmap window; vmemmap_populate() then\nwraps the memmap range around and maps it into low memory, silently\ncorrupting the page tables. The same search also picked the top-of-\naddress-space region that crashed memmap_init_zone_device() with amdkfd\non Loongson-3C6000 in 6.16 [1]; the commit 2969b42c8f99 (\"LoongArch/mm:\nalign vmemmap to maximal folio size\") keeps that region in bounds on\ncurrent Loongson-3C6000 configs, but CPUs with smaller cpu_pabits (e.g.\nthe Loongson-2K series) are still affected.\n\nDefine DIRECT_MAP_PHYSMEM_END as the vmemmap-covered physical range,\n(1ULL \u003c\u003c (cpu_pabits + 1)) - 1, capped at (1ULL \u003c\u003c MAX_PHYSMEM_BITS) - 1\nunder CONFIG_SPARSEMEM, similar to the commit f3336b48cf9d (\"riscv: mm:\nDefine DIRECT_MAP_PHYSMEM_END\").\n\n[1] https://lore.kernel.org/amd-gfx/20250814032153.227285-1-jeffbai@aosc.io/",
  "id": "CVE-2026-93237",
  "modified": "2026-09-27T03:30:34.069539875Z",
  "published": "2026-09-24T15:33:51.702Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2677f97a67fdbc62a82ce1faa67791f54451d36f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55e18311c705cceef6c34d522ea387b1f0069bab"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ab275a23b4d9f04ca6c2f5f6a3246194e045a761"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93237.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93237"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "LoongArch: Add DIRECT_MAP_PHYSMEM_END definition"
}