FKIE_CVE-2025-39715

Vulnerability from fkie_nvd - Published: 2025-09-05 18:15 - Updated: 2025-11-03 18:16
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: parisc: Revise gateway LWS calls to probe user read access We use load and stbys,e instructions to trigger memory reference interruptions without writing to memory. Because of the way read access support is implemented, read access interruptions are only triggered at privilege levels 2 and 3. The kernel and gateway page execute at privilege level 0, so this code never triggers a read access interruption. Thus, it is currently possible for user code to execute a LWS compare and swap operation at an address that is read protected at privilege level 3 (PRIV_USER). Fix this by probing read access rights at privilege level 3 and branching to lws_fault if access isn't allowed.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8bccf47adbf658293528e86960e6d6f736b1c9f7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9b6af875baba9c4679b55f4561e201485451305f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bc0a24c24ceebabb5ba65900e332233d79e625e6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e8b496c52aa0c6572d88db7cab85aeea6f9c194d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nparisc: Revise gateway LWS calls to probe user read access\n\nWe use load and stbys,e instructions to trigger memory reference\ninterruptions without writing to memory. Because of the way read\naccess support is implemented, read access interruptions are only\ntriggered at privilege levels 2 and 3. The kernel and gateway\npage execute at privilege level 0, so this code never triggers\na read access interruption. Thus, it is currently possible for\nuser code to execute a LWS compare and swap operation at an\naddress that is read protected at privilege level 3 (PRIV_USER).\n\nFix this by probing read access rights at privilege level 3 and\nbranching to lws_fault if access isn\u0027t allowed."
    }
  ],
  "id": "CVE-2025-39715",
  "lastModified": "2025-11-03T18:16:43.887",
  "metrics": {},
  "published": "2025-09-05T18:15:48.990",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8bccf47adbf658293528e86960e6d6f736b1c9f7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9b6af875baba9c4679b55f4561e201485451305f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bc0a24c24ceebabb5ba65900e332233d79e625e6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e8b496c52aa0c6572d88db7cab85aeea6f9c194d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8"
    },
    {
      "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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