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GHSA-3P6P-HF89-XH98

Vulnerability from github – Published: 2026-07-24 18:31 – Updated: 2026-08-12 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

kernel/fork: clear PF_BLOCK_TS in copy_process()

PF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is non-NULL, and blk_finish_plug() clears it via __blk_flush_plug() before NULLing the plug pointer. copy_process() breaks the invariant by inheriting PF_BLOCK_TS from the parent while resetting the child's plug to NULL.

Clear PF_BLOCK_TS alongside that assignment so callers can rely on "PF_BLOCK_TS set implies current->plug != NULL" and dereference current->plug unguarded.

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64253"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-24T16:16:55Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nkernel/fork: clear PF_BLOCK_TS in copy_process()\n\nPF_BLOCK_TS is only set in blk_time_get_ns() when current-\u003eplug is\nnon-NULL, and blk_finish_plug() clears it via __blk_flush_plug()\nbefore NULLing the plug pointer.  copy_process() breaks the\ninvariant by inheriting PF_BLOCK_TS from the parent while resetting\nthe child\u0027s plug to NULL.\n\nClear PF_BLOCK_TS alongside that assignment so callers can rely on\n\"PF_BLOCK_TS set implies current-\u003eplug != NULL\" and dereference\ncurrent-\u003eplug unguarded.",
  "id": "GHSA-3p6p-hf89-xh98",
  "modified": "2026-08-12T18:31:03Z",
  "published": "2026-07-24T18:31:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64253"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/77bba61a20f1b3d206f4f90e10a7bb3cd90b9619"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/99e6c712cc300883b8cbf03347d5359ec1a4d6dd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ee0801aceabdf583392477baf69a290b09448b8f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fd38b75c4b43295b10d69772a46d1c74dbd6fc81"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64253 (GCVE-0-2026-64253)

Vulnerability from cvelistv5 – Published: 2026-07-24 15:31 – Updated: 2026-08-17 04:52

Title

kernel/fork: clear PF_BLOCK_TS in copy_process()

Summary

In the Linux kernel, the following vulnerability has been resolved: kernel/fork: clear PF_BLOCK_TS in copy_process() PF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is non-NULL, and blk_finish_plug() clears it via __blk_flush_plug() before NULLing the plug pointer. copy_process() breaks the invariant by inheriting PF_BLOCK_TS from the parent while resetting the child's plug to NULL. Clear PF_BLOCK_TS alongside that assignment so callers can rely on "PF_BLOCK_TS set implies current->plug != NULL" and dereference current->plug unguarded.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/ee0801aceabdf5833…
https://git.kernel.org/stable/c/99e6c712cc300883b…
https://git.kernel.org/stable/c/77bba61a20f1b3d20…
https://git.kernel.org/stable/c/fd38b75c4b43295b1…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 06b23f92af87a84d70881b2ecaa72e00f7838264 , < ee0801aceabdf583392477baf69a290b09448b8f (git) Affected: 06b23f92af87a84d70881b2ecaa72e00f7838264 , < 99e6c712cc300883b8cbf03347d5359ec1a4d6dd (git) Affected: 06b23f92af87a84d70881b2ecaa72e00f7838264 , < 77bba61a20f1b3d206f4f90e10a7bb3cd90b9619 (git) Affected: 06b23f92af87a84d70881b2ecaa72e00f7838264 , < fd38b75c4b43295b10d69772a46d1c74dbd6fc81 (git)
Linux	Linux	Affected: 6.9 Unaffected: 0 , < 6.9 (semver) Unaffected: 6.12.95 , ≤ 6.12.* (semver) Unaffected: 6.18.38 , ≤ 6.18.* (semver) Unaffected: 7.1.3 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
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        {
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          "programFiles": [
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              "version": "0",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkernel/fork: clear PF_BLOCK_TS in copy_process()\n\nPF_BLOCK_TS is only set in blk_time_get_ns() when current-\u003eplug is\nnon-NULL, and blk_finish_plug() clears it via __blk_flush_plug()\nbefore NULLing the plug pointer.  copy_process() breaks the\ninvariant by inheriting PF_BLOCK_TS from the parent while resetting\nthe child\u0027s plug to NULL.\n\nClear PF_BLOCK_TS alongside that assignment so callers can rely on\n\"PF_BLOCK_TS set implies current-\u003eplug != NULL\" and dereference\ncurrent-\u003eplug unguarded."
        }
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}

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.
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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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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.

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GHSA-3P6P-HF89-XH98

CVE-2026-64253 (GCVE-0-2026-64253)

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