CVE-2025-40201 (GCVE-0-2025-40201)

Vulnerability from cvelistv5 – Published: 2025-11-12 21:56 – Updated: 2026-05-11 21:44
VLAI
Title
kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
Summary
In the Linux kernel, the following vulnerability has been resolved: kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths The usage of task_lock(tsk->group_leader) in sys_prlimit64()->do_prlimit() path is very broken. sys_prlimit64() does get_task_struct(tsk) but this only protects task_struct itself. If tsk != current and tsk is not a leader, this process can exit/exec and task_lock(tsk->group_leader) may use the already freed task_struct. Another problem is that sys_prlimit64() can race with mt-exec which changes ->group_leader. In this case do_prlimit() may take the wrong lock, or (worse) ->group_leader may change between task_lock() and task_unlock(). Change sys_prlimit64() to take tasklist_lock when necessary. This is not nice, but I don't see a better fix for -stable.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 18c91bb2d87268d23868bf13508f5bc9cf04e89a , < 1bc0d9315ef5296abb2c9fd840336255850ded18 (git)
Affected: 18c91bb2d87268d23868bf13508f5bc9cf04e89a , < 132f827e7bac7373e1522e89709d70b43cae5342 (git)
Affected: 18c91bb2d87268d23868bf13508f5bc9cf04e89a , < 19b45c84bd9fd42fa97ff80c6350d604cb871c75 (git)
Affected: 18c91bb2d87268d23868bf13508f5bc9cf04e89a , < 6796412decd2d8de8ec708213bbc958fab72f143 (git)
Affected: 18c91bb2d87268d23868bf13508f5bc9cf04e89a , < a15f37a40145c986cdf289a4b88390f35efdecc4 (git)
Create a notification for this product.
Linux Linux Affected: 5.18
Unaffected: 0 , < 5.18 (semver)
Unaffected: 6.1.157 , ≤ 6.1.* (semver)
Unaffected: 6.6.113 , ≤ 6.6.* (semver)
Unaffected: 6.12.54 , ≤ 6.12.* (semver)
Unaffected: 6.17.4 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/sys.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1bc0d9315ef5296abb2c9fd840336255850ded18",
              "status": "affected",
              "version": "18c91bb2d87268d23868bf13508f5bc9cf04e89a",
              "versionType": "git"
            },
            {
              "lessThan": "132f827e7bac7373e1522e89709d70b43cae5342",
              "status": "affected",
              "version": "18c91bb2d87268d23868bf13508f5bc9cf04e89a",
              "versionType": "git"
            },
            {
              "lessThan": "19b45c84bd9fd42fa97ff80c6350d604cb871c75",
              "status": "affected",
              "version": "18c91bb2d87268d23868bf13508f5bc9cf04e89a",
              "versionType": "git"
            },
            {
              "lessThan": "6796412decd2d8de8ec708213bbc958fab72f143",
              "status": "affected",
              "version": "18c91bb2d87268d23868bf13508f5bc9cf04e89a",
              "versionType": "git"
            },
            {
              "lessThan": "a15f37a40145c986cdf289a4b88390f35efdecc4",
              "status": "affected",
              "version": "18c91bb2d87268d23868bf13508f5bc9cf04e89a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/sys.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.54",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.157",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.113",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.54",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.4",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkernel/sys.c: fix the racy usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64() paths\n\nThe usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64()-\u003edo_prlimit()\npath is very broken.\n\nsys_prlimit64() does get_task_struct(tsk) but this only protects task_struct\nitself. If tsk != current and tsk is not a leader, this process can exit/exec\nand task_lock(tsk-\u003egroup_leader) may use the already freed task_struct.\n\nAnother problem is that sys_prlimit64() can race with mt-exec which changes\n-\u003egroup_leader. In this case do_prlimit() may take the wrong lock, or (worse)\n-\u003egroup_leader may change between task_lock() and task_unlock().\n\nChange sys_prlimit64() to take tasklist_lock when necessary. This is not\nnice, but I don\u0027t see a better fix for -stable."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:44:42.955Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18"
        },
        {
          "url": "https://git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342"
        },
        {
          "url": "https://git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75"
        },
        {
          "url": "https://git.kernel.org/stable/c/6796412decd2d8de8ec708213bbc958fab72f143"
        },
        {
          "url": "https://git.kernel.org/stable/c/a15f37a40145c986cdf289a4b88390f35efdecc4"
        }
      ],
      "title": "kernel/sys.c: fix the racy usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64() paths",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40201",
    "datePublished": "2025-11-12T21:56:34.063Z",
    "dateReserved": "2025-04-16T07:20:57.178Z",
    "dateUpdated": "2026-05-11T21:44:42.955Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-40201",
      "date": "2026-06-07",
      "epss": "0.00029",
      "percentile": "0.08932"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-40201\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-11-12T22:15:47.283\",\"lastModified\":\"2025-11-14T16:42:30.503\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nkernel/sys.c: fix the racy usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64() paths\\n\\nThe usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64()-\u003edo_prlimit()\\npath is very broken.\\n\\nsys_prlimit64() does get_task_struct(tsk) but this only protects task_struct\\nitself. If tsk != current and tsk is not a leader, this process can exit/exec\\nand task_lock(tsk-\u003egroup_leader) may use the already freed task_struct.\\n\\nAnother problem is that sys_prlimit64() can race with mt-exec which changes\\n-\u003egroup_leader. In this case do_prlimit() may take the wrong lock, or (worse)\\n-\u003egroup_leader may change between task_lock() and task_unlock().\\n\\nChange sys_prlimit64() to take tasklist_lock when necessary. This is not\\nnice, but I don\u0027t see a better fix for -stable.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6796412decd2d8de8ec708213bbc958fab72f143\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a15f37a40145c986cdf289a4b88390f35efdecc4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.