fkie_cve-2025-39716
Vulnerability from fkie_nvd
Published
2025-09-05 18:15
Modified
2025-11-03 18:16
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: parisc: Revise __get_user() to probe user read access Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel executes at privilege level 0, so __get_user() never triggers a read access interruption (code 26). Thus, it is currently possible for user code to access a read protected address via a system call. Fix this by probing read access rights at privilege level 3 (PRIV_USER) and setting __gu_err to -EFAULT (-14) if access isn't allowed. Note the cmpiclr instruction does a 32-bit compare because COND macro doesn't work inside asm.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/28a9b71671fb4a2993ef85b8ef6f117ea63894fe
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4c981077255acc2ed5b3df6e8dd0125c81b626a9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/741b163e440683195b8fd4fc8495fcd0105c6ab7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/89f686a0fb6e473a876a9a60a13aec67a62b9a7e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f410ef9a032caf98117256b22139c31342d7bb06
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nparisc: Revise __get_user() to probe user read access\n\nBecause of the way read access support is implemented, read access\ninterruptions are only triggered at privilege levels 2 and 3. The\nkernel executes at privilege level 0, so __get_user() never triggers\na read access interruption (code 26). Thus, it is currently possible\nfor user code to access a read protected address via a system call.\n\nFix this by probing read access rights at privilege level 3 (PRIV_USER)\nand setting __gu_err to -EFAULT (-14) if access isn\u0027t allowed.\n\nNote the cmpiclr instruction does a 32-bit compare because COND macro\ndoesn\u0027t work inside asm."
    }
  ],
  "id": "CVE-2025-39716",
  "lastModified": "2025-11-03T18:16:44.140",
  "metrics": {},
  "published": "2025-09-05T18:15:49.123",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/28a9b71671fb4a2993ef85b8ef6f117ea63894fe"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4c981077255acc2ed5b3df6e8dd0125c81b626a9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/741b163e440683195b8fd4fc8495fcd0105c6ab7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/89f686a0fb6e473a876a9a60a13aec67a62b9a7e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f410ef9a032caf98117256b22139c31342d7bb06"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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