FKIE_CVE-2026-46173

Vulnerability from fkie_nvd - Published: 2026-05-28 10:16 - Updated: 2026-09-08 09:18
Summary
In the Linux kernel, the following vulnerability has been resolved: exit: prevent preemption of oopsing TASK_DEAD task When an already-exiting task oopses, make_task_dead() currently calls do_task_dead() with preemption enabled. That is forbidden: do_task_dead() calls __schedule(), which has a comment saying "WARNING: must be called with preemption disabled!". If an oopsing task is preempted in do_task_dead(), between becoming TASK_DEAD and entering the scheduler explicitly, bad things happen: finish_task_switch() assumes that once the scheduler has switched away from a TASK_DEAD task, the task can never run again and its stack is no longer needed; but that assumption apparently doesn't hold if the dead task was preempted (the SM_PREEMPT case). This means that the scheduler ends up repeatedly dropping references on the dead task's stack, which can lead to use-after-free or double-free of the entire task stack; in other words, two tasks can end up running on the same stack, resulting in various kinds of memory corruption. (This does not just affect "recursively oopsing" tasks; it is enough to oops once during task exit, for example in a file_operations::release handler)

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/exit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3d6fb8a7690c23e3213c4b008f64d89a44b98737",
              "status": "affected",
              "version": "7f80a2fd7db9a55894fd841915236aca611291b5",
              "versionType": "git"
            },
            {
              "lessThan": "640b4c00fb0e2920327435f6176cbefc3c546165",
              "status": "affected",
              "version": "7f80a2fd7db9a55894fd841915236aca611291b5",
              "versionType": "git"
            },
            {
              "lessThan": "7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34",
              "status": "affected",
              "version": "7f80a2fd7db9a55894fd841915236aca611291b5",
              "versionType": "git"
            },
            {
              "lessThan": "6f49f94f3b11fe8bff1bf2a054143789e76aaf17",
              "status": "affected",
              "version": "7f80a2fd7db9a55894fd841915236aca611291b5",
              "versionType": "git"
            },
            {
              "lessThan": "9756b3db5db6c2f5eccb32dddbd88eb4c54f575e",
              "status": "affected",
              "version": "7f80a2fd7db9a55894fd841915236aca611291b5",
              "versionType": "git"
            },
            {
              "lessThan": "c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891",
              "status": "affected",
              "version": "7f80a2fd7db9a55894fd841915236aca611291b5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/exit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "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": "6.12.88",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "affectedData": [
        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unknown",
          "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "*",
              "status": "affected",
              "version": "V3.1.6",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "51CAD64E-2216-4DC6-BD41-143581752F8E",
              "versionEndExcluding": "6.1.175",
              "versionStartIncluding": "5.17",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A1A92866-F406-43B5-B2D1-CFC274753E9D",
              "versionEndExcluding": "6.6.140",
              "versionStartIncluding": "6.2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5AFBE0EC-CCDF-4207-AE92-ABF958125CA4",
              "versionEndExcluding": "6.12.88",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "BF39AE08-AE6D-4410-8FBE-76F6BF5BF55B",
              "versionEndExcluding": "6.18.30",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D0893CA7-9AE6-4DFE-AC75-48967D73AD8E",
              "versionEndExcluding": "7.0.7",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nexit: prevent preemption of oopsing TASK_DEAD task\n\nWhen an already-exiting task oopses, make_task_dead() currently calls\ndo_task_dead() with preemption enabled.  That is forbidden:\ndo_task_dead() calls __schedule(), which has a comment saying \"WARNING:\nmust be called with preemption disabled!\".\n\nIf an oopsing task is preempted in do_task_dead(), between becoming\nTASK_DEAD and entering the scheduler explicitly, bad things happen:\nfinish_task_switch() assumes that once the scheduler has switched away\nfrom a TASK_DEAD task, the task can never run again and its stack is no\nlonger needed; but that assumption apparently doesn\u0027t hold if the dead\ntask was preempted (the SM_PREEMPT case).\n\nThis means that the scheduler ends up repeatedly dropping references on\nthe dead task\u0027s stack, which can lead to use-after-free or double-free\nof the entire task stack; in other words, two tasks can end up running\non the same stack, resulting in various kinds of memory corruption.\n\n(This does not just affect \"recursively oopsing\" tasks; it is enough to\noops once during task exit, for example in a file_operations::release\nhandler)"
    }
  ],
  "id": "CVE-2026-46173",
  "lastModified": "2026-09-08T09:18:08.613",
  "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": "2026-05-28T10:16:32.923",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3d6fb8a7690c23e3213c4b008f64d89a44b98737"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/640b4c00fb0e2920327435f6176cbefc3c546165"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/6f49f94f3b11fe8bff1bf2a054143789e76aaf17"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/9756b3db5db6c2f5eccb32dddbd88eb4c54f575e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://project-zero.issues.chromium.org/issues/510793286"
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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