CVE-2025-68250 (GCVE-0-2025-68250)

Vulnerability from cvelistv5 – Published: 2025-12-16 14:32 – Updated: 2026-08-05 12:10
VLAI
Title
hung_task: fix warnings caused by unaligned lock pointers
Summary
In the Linux kernel, the following vulnerability has been resolved: hung_task: fix warnings caused by unaligned lock pointers The blocker tracking mechanism assumes that lock pointers are at least 4-byte aligned to use their lower bits for type encoding. However, as reported by Eero Tamminen, some architectures like m68k only guarantee 2-byte alignment of 32-bit values. This breaks the assumption and causes two related WARN_ON_ONCE checks to trigger. To fix this, the runtime checks are adjusted to silently ignore any lock that is not 4-byte aligned, effectively disabling the feature in such cases and avoiding the related warnings. Thanks to Geert Uytterhoeven for bisecting!
Severity
8.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: e711faaafbe54a884f33b53472434063d342f6d4 , < c0e2dcbe54cb15ecdf9d8f4501c6720423243888 (git)
Affected: e711faaafbe54a884f33b53472434063d342f6d4 , < c97513cddcfc235f2522617980838e500af21d01 (git)
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Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.17.6 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
          "programFiles": [
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        }
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              "value": "AV:N - On an affected m68k system running ksmbd, remote SMB2 IPC-pipe requests can contend on the unaligned session RPC rwsem and reach the vulnerable blocker tracking code over TCP/445.\nAC:L - The client can deterministically trigger the contemporaneous recursive-lock path or control concurrent requests against one session, so exploitation requires no uncontrollable race or memory-layout manipulation.\nPR:N - KSMBD permits passwordless guest sessions and allows restricted guest RPC operations, making the path reachable without credentials in a reasonable guest-enabled deployment.\nUI:N - Once the service is configured, attacker-supplied SMB requests trigger the vulnerable path without victim action.\nS:U - The warning, information exposure, and possible panic affect the same kernel and host security authority as the vulnerable code.\nC:L - The warning dumps kernel addresses and up to 48 raw m68k stack words, providing a bounded information disclosure where the kernel log or console is accessible.\nI:N - The rejected unaligned pointer is never stored or dereferenced, and the bug causes no memory corruption or attacker-controlled data modification.\nA:H - The warning immediately panics the kernel when panic_on_warn is enabled or the warning limit is reached, causing complete host unavailability."
            }
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        "dateUpdated": "2026-08-05T12:10:27.999Z",
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        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/c97513cddcfc235f2522617980838e500af21d01"
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    "datePublished": "2025-12-16T14:32:17.173Z",
    "dateReserved": "2025-12-16T13:41:40.266Z",
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    "state": "PUBLISHED"
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          }
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        "lastModified": "2026-07-30T06:24:34.843",
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      "source": "Red Hat CSAF VEX",
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      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-68250.json",
      "version": "8"
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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.
  • 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.



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.