{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-39845",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2025-39845"
  ],
  "published": "2025-09-19T15:28:22Z",
  "summary": "x86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()\n\nDefine ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure\npage tables are properly synchronized when calling p*d_populate_kernel().\n\nFor 5-level paging, synchronization is performed via\npgd_populate_kernel().  In 4-level paging, pgd_populate() is a no-op, so\nsynchronization is instead performed at the P4D level via\np4d_populate_kernel().\n\nThis fixes intermittent boot failures on systems using 4-level paging and\na large amount of persistent memory:\n\n  BUG: unable to handle page fault for address: ffffe70000000034\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  PGD 0 P4D 0\n  Oops: 0002 [#1] SMP NOPTI\n  RIP: 0010:__init_single_page+0x9/0x6d\n  Call Trace:\n   <TASK>\n   __init_zone_device_page+0x17/0x5d\n   memmap_init_zone_device+0x154/0x1bb\n   pagemap_range+0x2e0/0x40f\n   memremap_pages+0x10b/0x2f0\n   devm_memremap_pages+0x1e/0x60\n   dev_dax_probe+0xce/0x2ec [device_dax]\n   dax_bus_probe+0x6d/0xc9\n   [... snip ...]\n   </TASK>\n\nIt also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap\nbefore sync_global_pgds() [1]:\n\n  BUG: unable to handle page fault for address: ffffeb3ff1200000\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  PGD 0 P4D 0\n  Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI\n  Tainted: [W]=WARN\n  RIP: 0010:vmemmap_set_pmd+0xff/0x230\n   <TASK>\n   vmemmap_populate_hugepages+0x176/0x180\n   vmemmap_populate+0x34/0x80\n   __populate_section_memmap+0x41/0x90\n   sparse_add_section+0x121/0x3e0\n   __add_pages+0xba/0x150\n   add_pages+0x1d/0x70\n   memremap_pages+0x3dc/0x810\n   devm_memremap_pages+0x1c/0x60\n   xe_devm_add+0x8b/0x100 [xe]\n   xe_tile_init_noalloc+0x6a/0x70 [xe]\n   xe_device_probe+0x48c/0x740 [xe]\n   [... snip ...]",
  "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": "6.1.151",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-39845"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/744ff519c72de31344a627eaf9b24e9595aae554"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5f761d40ee95d2624f839c90ebeef2d5c55007f5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/26ff568f390a531d1bd792e49f1a401849921960"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b7f4051dd3388edd30e9a6077c05c486aa31e0d4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6bf9473727569e8283c1e2445c7ac42cf4fc9fa9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6659d027998083fbb6d42a165b0c90dc2e8ba989"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}