{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "fc9c45b71f43cafcc0435dd4c7a2d3b99955a0fa"
            },
            {
              "fixed": "91d011efe30aedde067ce6d218d521cf99b162e5"
            },
            {
              "fixed": "a564ccfe300fa6a065beda06ab7f3c140d6b4d63"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21933.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\narm: pgtable: fix NULL pointer dereference issue\n\nWhen update_mmu_cache_range() is called by update_mmu_cache(), the vmf\nparameter is NULL, which will cause a NULL pointer dereference issue in\nadjust_pte():\n\nUnable to handle kernel NULL pointer dereference at virtual address 00000030 when read\nHardware name: Atmel AT91SAM9\nPC is at update_mmu_cache_range+0x1e0/0x278\nLR is at pte_offset_map_rw_nolock+0x18/0x2c\nCall trace:\n update_mmu_cache_range from remove_migration_pte+0x29c/0x2ec\n remove_migration_pte from rmap_walk_file+0xcc/0x130\n rmap_walk_file from remove_migration_ptes+0x90/0xa4\n remove_migration_ptes from migrate_pages_batch+0x6d4/0x858\n migrate_pages_batch from migrate_pages+0x188/0x488\n migrate_pages from compact_zone+0x56c/0x954\n compact_zone from compact_node+0x90/0xf0\n compact_node from kcompactd+0x1d4/0x204\n kcompactd from kthread+0x120/0x12c\n kthread from ret_from_fork+0x14/0x38\nException stack(0xc0d8bfb0 to 0xc0d8bff8)\n\nTo fix it, do not rely on whether 'ptl' is equal to decide whether to hold\nthe pte lock, but decide it by whether CONFIG_SPLIT_PTE_PTLOCKS is\nenabled.  In addition, if two vmas map to the same PTE page, there is no\nneed to hold the pte lock again, otherwise a deadlock will occur.  Just\nadd the need_lock parameter to let adjust_pte() know this information.",
  "id": "CVE-2025-21933",
  "modified": "2026-04-01T23:08:50.139274630Z",
  "published": "2025-04-01T15:41:02.300Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91d011efe30aedde067ce6d218d521cf99b162e5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a564ccfe300fa6a065beda06ab7f3c140d6b4d63"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21933.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21933"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "arm: pgtable: fix NULL pointer dereference issue"
}