CVE-2025-68240 (GCVE-0-2025-68240)

Vulnerability from cvelistv5 – Published: 2025-12-16 14:21 – Updated: 2026-05-11 21:49
VLAI
Title
nilfs2: avoid having an active sc_timer before freeing sci
Summary
In the Linux kernel, the following vulnerability has been resolved: nilfs2: avoid having an active sc_timer before freeing sci Because kthread_stop did not stop sc_task properly and returned -EINTR, the sc_timer was not properly closed, ultimately causing the problem [1] reported by syzbot when freeing sci due to the sc_timer not being closed. Because the thread sc_task main function nilfs_segctor_thread() returns 0 when it succeeds, when the return value of kthread_stop() is not 0 in nilfs_segctor_destroy(), we believe that it has not properly closed sc_timer. We use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and set the value of sc_task to NULL under the protection of lock sc_state_lock, so as to avoid the issue caused by sc_timer not being properly shutdowned. [1] ODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout Call trace: nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline] nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877 nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6664 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 3f66cc261ccb54a8e4d8d5aa51c389c19453b00c , < 36049e81dc7f077e0e24d5b9688a7458beacef8f (git)
Affected: 3f66cc261ccb54a8e4d8d5aa51c389c19453b00c , < 2f65799e2a736d556d306440c4e1e8906736117a (git)
Affected: 3f66cc261ccb54a8e4d8d5aa51c389c19453b00c , < 9a6b60cb147d53968753a34805211d2e5e08c027 (git)
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Linux Linux Affected: 6.12
Unaffected: 0 , < 6.12 (semver)
Unaffected: 6.12.59 , ≤ 6.12.* (semver)
Unaffected: 6.17.9 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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          "product": "Linux",
          "programFiles": [
            "fs/nilfs2/segment.c"
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: avoid having an active sc_timer before freeing sci\n\nBecause kthread_stop did not stop sc_task properly and returned -EINTR,\nthe sc_timer was not properly closed, ultimately causing the problem [1]\nreported by syzbot when freeing sci due to the sc_timer not being closed.\n\nBecause the thread sc_task main function nilfs_segctor_thread() returns 0\nwhen it succeeds, when the return value of kthread_stop() is not 0 in\nnilfs_segctor_destroy(), we believe that it has not properly closed\nsc_timer.\n\nWe use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and\nset the value of sc_task to NULL under the protection of lock\nsc_state_lock, so as to avoid the issue caused by sc_timer not being\nproperly shutdowned.\n\n[1]\nODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout\nCall trace:\n nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline]\n nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877\n nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509"
        }
      ],
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        "dateUpdated": "2026-05-11T21:49:32.618Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/36049e81dc7f077e0e24d5b9688a7458beacef8f"
        },
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          "url": "https://git.kernel.org/stable/c/2f65799e2a736d556d306440c4e1e8906736117a"
        },
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          "url": "https://git.kernel.org/stable/c/9a6b60cb147d53968753a34805211d2e5e08c027"
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      ],
      "title": "nilfs2: avoid having an active sc_timer before freeing sci",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2025-68240",
    "datePublished": "2025-12-16T14:21:17.710Z",
    "dateReserved": "2025-12-16T13:41:40.263Z",
    "dateUpdated": "2026-05-11T21:49:32.618Z",
    "state": "PUBLISHED"
  },
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      "date": "2026-10-17",
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    "nvd": {
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                "product": "Linux",
                "programFiles": [
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                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
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        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: avoid having an active sc_timer before freeing sci\n\nBecause kthread_stop did not stop sc_task properly and returned -EINTR,\nthe sc_timer was not properly closed, ultimately causing the problem [1]\nreported by syzbot when freeing sci due to the sc_timer not being closed.\n\nBecause the thread sc_task main function nilfs_segctor_thread() returns 0\nwhen it succeeds, when the return value of kthread_stop() is not 0 in\nnilfs_segctor_destroy(), we believe that it has not properly closed\nsc_timer.\n\nWe use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and\nset the value of sc_task to NULL under the protection of lock\nsc_state_lock, so as to avoid the issue caused by sc_timer not being\nproperly shutdowned.\n\n[1]\nODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout\nCall trace:\n nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline]\n nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877\n nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509"
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnilfs2: evitar tener un sc_timer activo antes de liberar sci\n\nDebido a que kthread_stop no detuvo sc_task correctamente y devolvi\u00f3 -EINTR, el sc_timer no se cerr\u00f3 correctamente, lo que finalmente caus\u00f3 el problema [1] reportado por syzbot al liberar sci debido a que el sc_timer no estaba cerrado.\n\nDebido a que la funci\u00f3n principal del hilo sc_task, nilfs_segctor_thread(), devuelve 0 cuando tiene \u00e9xito, cuando el valor de retorno de kthread_stop() no es 0 en nilfs_segctor_destroy(), creemos que no ha cerrado correctamente sc_timer.\n\nUsamos timer_shutdown_sync() para esperar sincr\u00f3nicamente a que sc_timer se apague, y establecer el valor de sc_task en NULL bajo la protecci\u00f3n del bloqueo sc_state_lock, para evitar el problema causado por el sc_timer al no haberse apagado correctamente.\n\n[1]\nODEBUG: objeto activo libre (estado activo 0): 00000000dacb411a tipo de objeto: timer_list pista: nilfs_construction_timeout\nTraza de llamada:\n nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline]\n nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877\n nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509"
          }
        ],
        "id": "CVE-2025-68240",
        "lastModified": "2026-10-14T13:10:00.187",
        "metrics": {},
        "published": "2025-12-16T15:15:53.173",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Deferred"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-30T10:32:18+00:00",
      "cve": "CVE-2025-68240",
      "id": "CVE-2025-68240",
      "initial_release_date": "2025-12-16T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: nilfs2: avoid having an active sc_timer before freeing sci",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-68240.json",
      "version": "3"
    }
  }
}



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