fkie_cve-2025-40218
Vulnerability from fkie_nvd
Published
2025-12-04 15:15
Modified
2025-12-04 17:15
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: do not repeat pte_offset_map_lock() until success DAMON's virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0ccd91cf749536d41307a07e60ec14ab0dbf21f5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/677ebfe5d00f94adec0c0204f6e6e2a82d3f77bf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ac42320ec873bfe726141069cfdd90ee5bc4e885
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b93af2cc8e036754c0d9970d9ddc47f43cc94b9f
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/vaddr: do not repeat pte_offset_map_lock() until success\n\nDAMON\u0027s virtual address space operation set implementation (vaddr) calls\npte_offset_map_lock() inside the page table walk callback function.  This\nis for reading and writing page table accessed bits.  If\npte_offset_map_lock() fails, it retries by returning the page table walk\ncallback function with ACTION_AGAIN.\n\npte_offset_map_lock() can continuously fail if the target is a pmd\nmigration entry, though.  Hence it could cause an infinite page table walk\nif the migration cannot be done until the page table walk is finished. \nThis indeed caused a soft lockup when CPU hotplugging and DAMON were\nrunning in parallel.\n\nAvoid the infinite loop by simply not retrying the page table walk.  DAMON\nis promising only a best-effort accuracy, so missing access to such pages\nis no problem."
    }
  ],
  "id": "CVE-2025-40218",
  "lastModified": "2025-12-04T17:15:08.283",
  "metrics": {},
  "published": "2025-12-04T15:15:57.643",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0ccd91cf749536d41307a07e60ec14ab0dbf21f5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/677ebfe5d00f94adec0c0204f6e6e2a82d3f77bf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ac42320ec873bfe726141069cfdd90ee5bc4e885"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b93af2cc8e036754c0d9970d9ddc47f43cc94b9f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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