CVE-2026-23274 (GCVE-0-2026-23274)

Vulnerability from cvelistv5 – Published: 2026-03-20 08:08 – Updated: 2026-03-20 08:08
VLAI?
Title
netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 68983a354a655c35d3fb204489d383a2a051fda7 , < f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 (git)
Affected: 68983a354a655c35d3fb204489d383a2a051fda7 , < f228b9ae2a7e84d1153616d8e71c4236cb1f1309 (git)
Affected: 68983a354a655c35d3fb204489d383a2a051fda7 , < 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf (git)
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    Linux Linux Affected: 5.7
Unaffected: 0 , < 5.7 (semver)
Unaffected: 6.18.19 , ≤ 6.18.* (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0-rc4 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/xt_IDLETIMER.c"
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          "vendor": "Linux",
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              "versionType": "git"
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.7"
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              "version": "0",
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            },
            {
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              "status": "unaffected",
              "version": "6.19.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
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                  "versionEndExcluding": "7.0-rc4",
                  "versionStartIncluding": "5.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels\n\nIDLETIMER revision 0 rules reuse existing timers by label and always call\nmod_timer() on timer-\u003etimer.\n\nIf the label was created first by revision 1 with XT_IDLETIMER_ALARM,\nthe object uses alarm timer semantics and timer-\u003etimer is never initialized.\nReusing that object from revision 0 causes mod_timer() on an uninitialized\ntimer_list, triggering debugobjects warnings and possible panic when\npanic_on_warn=1.\n\nFix this by rejecting revision 0 rule insertion when an existing timer with\nthe same label is of ALARM type."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-20T08:08:54.918Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1"
        },
        {
          "url": "https://git.kernel.org/stable/c/f228b9ae2a7e84d1153616d8e71c4236cb1f1309"
        },
        {
          "url": "https://git.kernel.org/stable/c/329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf"
        }
      ],
      "title": "netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels",
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23274",
    "datePublished": "2026-03-20T08:08:54.918Z",
    "dateReserved": "2026-01-13T15:37:45.991Z",
    "dateUpdated": "2026-03-20T08:08:54.918Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-23274\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-03-20T09:16:13.077\",\"lastModified\":\"2026-03-20T13:37:50.737\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnetfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels\\n\\nIDLETIMER revision 0 rules reuse existing timers by label and always call\\nmod_timer() on timer-\u003etimer.\\n\\nIf the label was created first by revision 1 with XT_IDLETIMER_ALARM,\\nthe object uses alarm timer semantics and timer-\u003etimer is never initialized.\\nReusing that object from revision 0 causes mod_timer() on an uninitialized\\ntimer_list, triggering debugobjects warnings and possible panic when\\npanic_on_warn=1.\\n\\nFix this by rejecting revision 0 rule insertion when an existing timer with\\nthe same label is of ALARM type.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\\n\\nnetfilter: xt_IDLETIMER: rechazar la reutilizaci\u00f3n de rev0 de etiquetas de temporizador ALARM\\n\\nLas reglas de la revisi\u00f3n 0 de IDLETIMER reutilizan temporizadores existentes por etiqueta y siempre llaman a mod_timer() en timer-\u0026gt;timer.\\n\\nSi la etiqueta fue creada primero por la revisi\u00f3n 1 con XT_IDLETIMER_ALARM, el objeto utiliza sem\u00e1ntica de temporizador de alarma y timer-\u0026gt;timer nunca se inicializa. Reutilizar ese objeto de la revisi\u00f3n 0 causa mod_timer() en una timer_list no inicializada, lo que activa advertencias de debugobjects y un posible p\u00e1nico cuando panic_on_warn=1.\\n\\nSolucione esto rechazando la inserci\u00f3n de reglas de la revisi\u00f3n 0 cuando un temporizador existente con la misma etiqueta es de tipo ALARM.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f228b9ae2a7e84d1153616d8e71c4236cb1f1309\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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  • 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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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.