{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-46847",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2024-46847"
  ],
  "published": "2024-09-27T12:40:05Z",
  "summary": "mm: vmalloc: ensure vmap_block is initialised before adding to queue",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: vmalloc: ensure vmap_block is initialised before adding to queue\n\nCommit 8c61291fd850 (\"mm: fix incorrect vbq reference in\npurge_fragmented_block\") extended the 'vmap_block' structure to contain a\n'cpu' field which is set at allocation time to the id of the initialising\nCPU.\n\nWhen a new 'vmap_block' is being instantiated by new_vmap_block(), the\npartially initialised structure is added to the local 'vmap_block_queue'\nxarray before the 'cpu' field has been initialised.  If another CPU is\nconcurrently walking the xarray (e.g.  via vm_unmap_aliases()), then it\nmay perform an out-of-bounds access to the remote queue thanks to an\nuninitialised index.\n\nThis has been observed as UBSAN errors in Android:\n\n | Internal error: UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP\n |\n | Call trace:\n |  purge_fragmented_block+0x204/0x21c\n |  _vm_unmap_aliases+0x170/0x378\n |  vm_unmap_aliases+0x1c/0x28\n |  change_memory_common+0x1dc/0x26c\n |  set_memory_ro+0x18/0x24\n |  module_enable_ro+0x98/0x238\n |  do_init_module+0x1b0/0x310\n\nMove the initialisation of 'vb->cpu' in new_vmap_block() ahead of the\naddition to the xarray.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.6.47-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-2712",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v6",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v7",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v7l",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v8",
            "binary_version": "1:6.6.47-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.6.47-1+rpt1": {
            "linux_commit": "cf64a1dfecc2dc418efdd61701c1a4b185ab4761",
            "upstream_version": "6.6.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.51"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-46847"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1b2770e27d6d952f491bb362b657e5b2713c3efd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6cf74e0e5e3ab5d5c9defb4c73dad54d52224671"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3e3de7947c751509027d26b679ecd243bc9db255"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z"
  }
}