FKIE_CVE-2026-97905

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-09-25 11:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: cpufreq: zero-initialize policy cpumask before sysfs publication cpufreq_policy_alloc() allocates policy->cpus with alloc_cpumask_var(), i.e. without __GFP_ZERO, unlike the sibling related_cpus and real_cpus masks. With CONFIG_CPUMASK_OFFSTACK=y the mask is a separate kmalloc_node() allocation, so its bitmap holds whatever the slab allocator left behind: cpufreq_online() cpufreq_policy_alloc() alloc_cpumask_var(&policy->cpus) /* bitmap is uninitialized */ kobject_init_and_add() /* policy%u/ appears in sysfs */ cpufreq_policy_online() cpumask_copy(policy->cpus, cpumask_of(cpu)) /* first valid value */ This leaves a window in which the sysfs attributes are already reachable while policy->cpus is still garbage. show()/store() gate on policy_is_inactive(), i.e. cpumask_empty(policy->cpus), so a non-zero bitmap makes them run the attribute callbacks on a policy that is not initialized yet. Fix this by using zalloc_cpumask_var() for policy->cpus.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0de2f3918fbbbb767e7e716178194b66560dd12a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/54d37bcf2f497140b9207968557ddb484058e749
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6e166b9281dec98aed19213a84235250e5fdb081
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bbc0472d2270bf732142ca71579d6ede636174ed
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/cpufreq/cpufreq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0de2f3918fbbbb767e7e716178194b66560dd12a",
              "status": "affected",
              "version": "2fc3384dc75bf7333384c7a16d12c796f61c3f56",
              "versionType": "git"
            },
            {
              "lessThan": "6e166b9281dec98aed19213a84235250e5fdb081",
              "status": "affected",
              "version": "2fc3384dc75bf7333384c7a16d12c796f61c3f56",
              "versionType": "git"
            },
            {
              "lessThan": "bbc0472d2270bf732142ca71579d6ede636174ed",
              "status": "affected",
              "version": "2fc3384dc75bf7333384c7a16d12c796f61c3f56",
              "versionType": "git"
            },
            {
              "lessThan": "54d37bcf2f497140b9207968557ddb484058e749",
              "status": "affected",
              "version": "2fc3384dc75bf7333384c7a16d12c796f61c3f56",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/cpufreq/cpufreq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.2"
            },
            {
              "lessThan": "4.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncpufreq: zero-initialize policy cpumask before sysfs publication\n\ncpufreq_policy_alloc() allocates policy-\u003ecpus with alloc_cpumask_var(),\ni.e. without __GFP_ZERO, unlike the sibling related_cpus and real_cpus\nmasks. With CONFIG_CPUMASK_OFFSTACK=y the mask is a separate\nkmalloc_node() allocation, so its bitmap holds whatever the slab allocator\nleft behind:\n\n  cpufreq_online()\n    cpufreq_policy_alloc()\n      alloc_cpumask_var(\u0026policy-\u003ecpus)    /* bitmap is uninitialized */\n      kobject_init_and_add()              /* policy%u/ appears in sysfs */\n    cpufreq_policy_online()\n      cpumask_copy(policy-\u003ecpus, cpumask_of(cpu))  /* first valid value */\n\nThis leaves a window in which the sysfs attributes are already reachable\nwhile policy-\u003ecpus is still garbage. show()/store() gate on\npolicy_is_inactive(), i.e. cpumask_empty(policy-\u003ecpus), so a non-zero\nbitmap makes them run the attribute callbacks on a policy that is not\ninitialized yet.\n\nFix this by using zalloc_cpumask_var() for policy-\u003ecpus."
    }
  ],
  "id": "CVE-2026-97905",
  "lastModified": "2026-09-25T11:17:17.403",
  "metrics": {},
  "published": "2026-09-25T11:17:17.403",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0de2f3918fbbbb767e7e716178194b66560dd12a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/54d37bcf2f497140b9207968557ddb484058e749"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6e166b9281dec98aed19213a84235250e5fdb081"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bbc0472d2270bf732142ca71579d6ede636174ed"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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