FKIE_CVE-2026-52933

Vulnerability from fkie_nvd - Published: 2026-06-24 08:16 - Updated: 2026-06-28 08:16
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/poll.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "81bf96b0abbfa4cd47ea32e12596aed3855fb2f3",
              "status": "affected",
              "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea",
              "versionType": "git"
            },
            {
              "lessThan": "cf522703d4f194991615763697ae25a3f9539763",
              "status": "affected",
              "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea",
              "versionType": "git"
            },
            {
              "lessThan": "fc47043f3d9af3efa407665b47f8378ec691ba18",
              "status": "affected",
              "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea",
              "versionType": "git"
            },
            {
              "lessThan": "ea0697129807d718037f618221037aa0660ee3c5",
              "status": "affected",
              "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea",
              "versionType": "git"
            },
            {
              "lessThan": "c6d191164dc81838d8dbf452a6000f68c558d1ae",
              "status": "affected",
              "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea",
              "versionType": "git"
            },
            {
              "lessThan": "326941b22806cbf2df1fbfe902b7908b368cce42",
              "status": "affected",
              "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "bc4e6ee16778149811333a969a7a893d4cc110c5",
              "versionType": "git"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.82",
              "versionType": "semver"
            },
            {
              "lessThan": "6.1",
              "status": "affected",
              "version": "6.0.11",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "io_uring/poll.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "lessThan": "6.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.140",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.86",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.27",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "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": "2026-06-28T08:16:24.653",
  "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",
      "url": "https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}


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