FKIE_CVE-2026-52933

Vulnerability from fkie_nvd - Published: 2026-06-24 08:16 - Updated: 2026-07-08 15:28
Summary
In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.

{
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            "io_uring/poll.c"
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          "vendor": "Linux",
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              "status": "unaffected",
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              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.12.86",
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              "status": "unaffected",
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              "versionType": "semver"
            },
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              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.4",
              "versionType": "semver"
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
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          "negate": false,
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/poll: fix signed comparison in io_poll_get_ownership()\n\nio_poll_get_ownership() uses a signed comparison to check whether\npoll_refs has reached the threshold for the slowpath:\n\n    if (unlikely(atomic_read(\u0026req-\u003epoll_refs) \u003e= IO_POLL_REF_BIAS))\n\natomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG\n(BIT(31)) is set in poll_refs, the value becomes negative in\nsigned arithmetic, so the \u003e= 128 comparison always evaluates to\nfalse and the slowpath is never taken.\n\nFix this by casting the atomic_read() result to unsigned int\nbefore the comparison, so that the cancel flag is treated as a\nlarge positive value and correctly triggers the slowpath."
    }
  ],
  "id": "CVE-2026-52933",
  "lastModified": "2026-07-08T15:28:00.520",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-24T08:16:23.480",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42"
    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    },
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    },
    {
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      "tags": [
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    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "url": "https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-835"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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