CVE-2025-39999 (GCVE-0-2025-39999)

Vulnerability from cvelistv5 – Published: 2025-10-15 07:58 – Updated: 2026-05-23 16:01
VLAI
Title
blk-mq: fix blk_mq_tags double free while nr_requests grown
Summary
In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix blk_mq_tags double free while nr_requests grown In the case user trigger tags grow by queue sysfs attribute nr_requests, hctx->sched_tags will be freed directly and replaced with a new allocated tags, see blk_mq_tag_update_depth(). The problem is that hctx->sched_tags is from elevator->et->tags, while et->tags is still the freed tags, hence later elevator exit will try to free the tags again, causing kernel panic. Fix this problem by replacing et->tags with new allocated tags as well. Noted there are still some long term problems that will require some refactor to be fixed thoroughly[1]. [1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 58567d8e95c096ad234963df90a2ca518901f4b6 , < 8faee580d63bc2a54a59dcdb7f9ce4de29384fec (git)
Affected: f5a6604f7a4405450e4a1f54e5430f47290c500f , < 392b1d64911f4de8887fe8b68299fa8bd6e5b923 (git)
Affected: f5a6604f7a4405450e4a1f54e5430f47290c500f , < ba28afbd9eff2a6370f23ef4e6a036ab0cfda409 (git)
Affected: 6.16.4 , < 6.16.11 (semver)
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Linux Linux Affected: 6.17
Unaffected: 0 , < 6.17 (semver)
Unaffected: 6.16.11 , ≤ 6.16.* (semver)
Unaffected: 6.17.1 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
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{
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix blk_mq_tags double free while nr_requests grown\n\nIn the case user trigger tags grow by queue sysfs attribute nr_requests,\nhctx-\u003esched_tags will be freed directly and replaced with a new\nallocated tags, see blk_mq_tag_update_depth().\n\nThe problem is that hctx-\u003esched_tags is from elevator-\u003eet-\u003etags, while\net-\u003etags is still the freed tags, hence later elevator exit will try to\nfree the tags again, causing kernel panic.\n\nFix this problem by replacing et-\u003etags with new allocated tags as well.\n\nNoted there are still some long term problems that will require some\nrefactor to be fixed thoroughly[1].\n\n[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/"
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    "cveId": "CVE-2025-39999",
    "datePublished": "2025-10-15T07:58:23.038Z",
    "dateReserved": "2025-04-16T07:20:57.151Z",
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    "state": "PUBLISHED"
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        "descriptions": [
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            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix blk_mq_tags double free while nr_requests grown\n\nIn the case user trigger tags grow by queue sysfs attribute nr_requests,\nhctx-\u003esched_tags will be freed directly and replaced with a new\nallocated tags, see blk_mq_tag_update_depth().\n\nThe problem is that hctx-\u003esched_tags is from elevator-\u003eet-\u003etags, while\net-\u003etags is still the freed tags, hence later elevator exit will try to\nfree the tags again, causing kernel panic.\n\nFix this problem by replacing et-\u003etags with new allocated tags as well.\n\nNoted there are still some long term problems that will require some\nrefactor to be fixed thoroughly[1].\n\n[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/"
          }
        ],
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        "metrics": {},
        "published": "2025-10-15T08:15:38.210",
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      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-39999.json",
      "version": "11"
    }
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}



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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

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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.
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  • 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.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.