Vulnerability-Lookup

rxsa-2026:49870

Vulnerability from osv_rocky

Published

2026-08-04 18:09

Modified

2026-08-06 00:11

Summary

Low: kernel security, bug fix, and enhancement update

Details

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

kernel: Linux kernel: Denial of Service due to NULL function pointer race in timer shutdown (CVE-2025-68214)

Bug Fix(es) and Enhancement(s):

Possible regression with FM350GL [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-184273)
Rocky Linux SIG Cloud9: Fix downstream-only regression from 532af53c [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-192430)
gfs2: xfstests generic/363 failure [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-214021)
Rocky Linux SIG Cloud 9: Backport b95e0e792822 [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-216471)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Severity

5.5 (Medium)


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

Credits

Rocky Enterprise Software Foundation

Red Hat

References

URL

Type

	https://errata.rockylinux.org/RXSA-2026:49870	ADVISORY
	https://bugzilla.redhat.com/show_bug.cgi?id=2422686	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Rocky Linux:9",
        "name": "kernel",
        "purl": "pkg:rpm/rocky-linux/kernel?distro=rocky-linux-9-sig-cloud\u0026epoch=0"
      },
      "ranges": [
        {
          "database_specific": {
            "yum_repository": "cloud-common"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0:5.14.0-687.34.1.el9_8.cloud.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "credits": [
    {
      "name": "Rocky Enterprise Software Foundation"
    },
    {
      "name": "Red Hat"
    }
  ],
  "details": "The kernel packages contain the Linux kernel, the core of any Linux operating system.\n\nSecurity Fix(es):\n\n* kernel: Linux kernel: Denial of Service due to NULL function pointer race in timer shutdown (CVE-2025-68214)\n\nBug Fix(es) and Enhancement(s):\n\n* Possible regression with FM350GL [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-184273)\n\n* Rocky Linux SIG Cloud9: Fix downstream-only regression from 532af53c [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-192430)\n\n* gfs2: xfstests generic/363 failure [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-214021)\n\n* Rocky Linux SIG Cloud 9: Backport b95e0e792822 [rhel-9.8.z] (JIRA:Rocky Linux SIG Cloud-216471)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.",
  "id": "RXSA-2026:49870",
  "modified": "2026-08-06T00:11:02.081751Z",
  "published": "2026-08-04T18:09:19.052573Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://errata.rockylinux.org/RXSA-2026:49870"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2422686"
    }
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Low: kernel security, bug fix, and enhancement update",
  "upstream": [
    "CVE-2025-68214"
  ]
}

CVE-2025-68214 (GCVE-0-2025-68214)

Vulnerability from cvelistv5 – Published: 2025-12-16 13:57 – Updated: 2026-05-23 16:02

Title

timers: Fix NULL function pointer race in timer_shutdown_sync()

Summary

In the Linux kernel, the following vulnerability has been resolved: timers: Fix NULL function pointer race in timer_shutdown_sync() There is a race condition between timer_shutdown_sync() and timer expiration that can lead to hitting a WARN_ON in expire_timers(). The issue occurs when timer_shutdown_sync() clears the timer function to NULL while the timer is still running on another CPU. The race scenario looks like this: CPU0 CPU1 <SOFTIRQ> lock_timer_base() expire_timers() base->running_timer = timer; unlock_timer_base() [call_timer_fn enter] mod_timer() ... timer_shutdown_sync() lock_timer_base() // For now, will not detach the timer but only clear its function to NULL if (base->running_timer != timer) ret = detach_if_pending(timer, base, true); if (shutdown) timer->function = NULL; unlock_timer_base() [call_timer_fn exit] lock_timer_base() base->running_timer = NULL; unlock_timer_base() ... // Now timer is pending while its function set to NULL. // next timer trigger <SOFTIRQ> expire_timers() WARN_ON_ONCE(!fn) // hit ... lock_timer_base() // Now timer will detach if (base->running_timer != timer) ret = detach_if_pending(timer, base, true); if (shutdown) timer->function = NULL; unlock_timer_base() The problem is that timer_shutdown_sync() clears the timer function regardless of whether the timer is currently running. This can leave a pending timer with a NULL function pointer, which triggers the WARN_ON_ONCE(!fn) check in expire_timers(). Fix this by only clearing the timer function when actually detaching the timer. If the timer is running, leave the function pointer intact, which is safe because the timer will be properly detached when it finishes running.

Severity

No CVSS data available.

Assigner

Linux

References

6 references

URL	Tags
https://git.kernel.org/stable/c/ba43ac025c4318241…
https://git.kernel.org/stable/c/1a975716cc8977f46…
https://git.kernel.org/stable/c/6665fbd7730b26d77…
https://git.kernel.org/stable/c/176725f4848376530…
https://git.kernel.org/stable/c/a01efa7a780c42ac5…
https://git.kernel.org/stable/c/20739af07383e6eb1…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: debbcf812d735003c96c5e5968a3cfa4e1fbd1af , < ba43ac025c4318241f8edf94f31d2eebab86991b (git) Affected: 334c33aa487be406a149c8b87c38c8399d2dba8d , < 1a975716cc8977f461e45e28e3e5977d46ad7a6a (git) Affected: 0cc04e80458a822300b93f82ed861a513edde194 , < 6665fbd7730b26d770c232b20d1b907e6a67a914 (git) Affected: 0cc04e80458a822300b93f82ed861a513edde194 , < 176725f4848376530a0f0da9023f956afcc33585 (git) Affected: 0cc04e80458a822300b93f82ed861a513edde194 , < a01efa7a780c42ac5170a949bd95c9786ffcc60a (git) Affected: 0cc04e80458a822300b93f82ed861a513edde194 , < 20739af07383e6eb1ec59dcd70b72ebfa9ac362c (git) Affected: 6.1.158 , < 6.1.159 (semver)
Linux	Linux	Affected: 6.2 Unaffected: 0 , < 6.2 (semver) Unaffected: 6.1.159 , ≤ 6.1.* (semver) Unaffected: 6.6.118 , ≤ 6.6.* (semver) Unaffected: 6.12.60 , ≤ 6.12.* (semver) Unaffected: 6.17.10 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/time/timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ba43ac025c4318241f8edf94f31d2eebab86991b",
              "status": "affected",
              "version": "debbcf812d735003c96c5e5968a3cfa4e1fbd1af",
              "versionType": "git"
            },
            {
              "lessThan": "1a975716cc8977f461e45e28e3e5977d46ad7a6a",
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              "version": "334c33aa487be406a149c8b87c38c8399d2dba8d",
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            },
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              "status": "affected",
              "version": "0cc04e80458a822300b93f82ed861a513edde194",
              "versionType": "git"
            },
            {
              "lessThan": "176725f4848376530a0f0da9023f956afcc33585",
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              "versionType": "git"
            },
            {
              "lessThan": "a01efa7a780c42ac5170a949bd95c9786ffcc60a",
              "status": "affected",
              "version": "0cc04e80458a822300b93f82ed861a513edde194",
              "versionType": "git"
            },
            {
              "lessThan": "20739af07383e6eb1ec59dcd70b72ebfa9ac362c",
              "status": "affected",
              "version": "0cc04e80458a822300b93f82ed861a513edde194",
              "versionType": "git"
            },
            {
              "lessThan": "6.1.159",
              "status": "affected",
              "version": "6.1.158",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/time/timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.159",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.118",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.60",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.10",
              "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": "6.1.159",
                  "versionStartIncluding": "6.1.158",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.118",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.2",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntimers: Fix NULL function pointer race in timer_shutdown_sync()\n\nThere is a race condition between timer_shutdown_sync() and timer\nexpiration that can lead to hitting a WARN_ON in expire_timers().\n\nThe issue occurs when timer_shutdown_sync() clears the timer function\nto NULL while the timer is still running on another CPU. The race\nscenario looks like this:\n\nCPU0\t\t\t\t\tCPU1\n\t\t\t\t\t\u003cSOFTIRQ\u003e\n\t\t\t\t\tlock_timer_base()\n\t\t\t\t\texpire_timers()\n\t\t\t\t\tbase-\u003erunning_timer = timer;\n\t\t\t\t\tunlock_timer_base()\n\t\t\t\t\t[call_timer_fn enter]\n\t\t\t\t\tmod_timer()\n\t\t\t\t\t...\ntimer_shutdown_sync()\nlock_timer_base()\n// For now, will not detach the timer but only clear its function to NULL\nif (base-\u003erunning_timer != timer)\n\tret = detach_if_pending(timer, base, true);\nif (shutdown)\n\ttimer-\u003efunction = NULL;\nunlock_timer_base()\n\t\t\t\t\t[call_timer_fn exit]\n\t\t\t\t\tlock_timer_base()\n\t\t\t\t\tbase-\u003erunning_timer = NULL;\n\t\t\t\t\tunlock_timer_base()\n\t\t\t\t\t...\n\t\t\t\t\t// Now timer is pending while its function set to NULL.\n\t\t\t\t\t// next timer trigger\n\t\t\t\t\t\u003cSOFTIRQ\u003e\n\t\t\t\t\texpire_timers()\n\t\t\t\t\tWARN_ON_ONCE(!fn) // hit\n\t\t\t\t\t...\nlock_timer_base()\n// Now timer will detach\nif (base-\u003erunning_timer != timer)\n\tret = detach_if_pending(timer, base, true);\nif (shutdown)\n\ttimer-\u003efunction = NULL;\nunlock_timer_base()\n\nThe problem is that timer_shutdown_sync() clears the timer function\nregardless of whether the timer is currently running. This can leave a\npending timer with a NULL function pointer, which triggers the\nWARN_ON_ONCE(!fn) check in expire_timers().\n\nFix this by only clearing the timer function when actually detaching the\ntimer. If the timer is running, leave the function pointer intact, which is\nsafe because the timer will be properly detached when it finishes running."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-23T16:02:22.475Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/ba43ac025c4318241f8edf94f31d2eebab86991b"
        },
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        },
        {
          "url": "https://git.kernel.org/stable/c/a01efa7a780c42ac5170a949bd95c9786ffcc60a"
        },
        {
          "url": "https://git.kernel.org/stable/c/20739af07383e6eb1ec59dcd70b72ebfa9ac362c"
        }
      ],
      "title": "timers: Fix NULL function pointer race in timer_shutdown_sync()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-68214",
    "datePublished": "2025-12-16T13:57:09.728Z",
    "dateReserved": "2025-12-16T13:41:40.256Z",
    "dateUpdated": "2026-05-23T16:02:22.475Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

rxsa-2026:49870

Vulnerability from osv_rocky

CVE-2025-68214 (GCVE-0-2025-68214)

Tags

Sightings

Nomenclature