Vulnerability-Lookup

GHSA-7CQC-FVGJ-QM9H

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31

Details

In the Linux kernel, the following vulnerability has been resolved:

cgroup/rstat: validate cpu before css_rstat_cpu() access

css_rstat_updated() is exposed as a BPF kfunc and accepts a caller-provided cpu argument. The function uses cpu for per-cpu rstat lookups without checking whether it refers to a valid possible CPU.

A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu == 0x7fffffff triggers:

UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9 index 2147483647 is out of range for type 'long unsigned int [64]' Call Trace: css_rstat_updated bpf_iter_run_prog cgroup_iter_seq_show bpf_seq_read

Add cpu validation to the BPF-facing css_rstat_updated() kfunc and move the common implementation to __css_rstat_updated() for in-kernel callers.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64036"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:43Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/rstat: validate cpu before css_rstat_cpu() access\n\ncss_rstat_updated() is exposed as a BPF kfunc and accepts a\ncaller-provided cpu argument. The function uses cpu for per-cpu rstat\nlookups without checking whether it refers to a valid possible CPU.\n\nA BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an\ninvalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==\n0x7fffffff triggers:\n\n  UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9\n  index 2147483647 is out of range for type \u0027long unsigned int [64]\u0027\n  Call Trace:\n    css_rstat_updated\n    bpf_iter_run_prog\n    cgroup_iter_seq_show\n    bpf_seq_read\n\nAdd cpu validation to the BPF-facing css_rstat_updated() kfunc and\nmove the common implementation to __css_rstat_updated() for in-kernel\ncallers.",
  "id": "GHSA-7cqc-fvgj-qm9h",
  "modified": "2026-07-20T15:31:56Z",
  "published": "2026-07-19T18:31:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64036"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8817005efbdfdf5d4e4814cb5dc52b53d12917d7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fd2bd9fa7700ddf28296486b2598cff2f80cc819"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64036 (GCVE-0-2026-64036)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-20 13:42

Title

cgroup/rstat: validate cpu before css_rstat_cpu() access

Summary

In the Linux kernel, the following vulnerability has been resolved: cgroup/rstat: validate cpu before css_rstat_cpu() access css_rstat_updated() is exposed as a BPF kfunc and accepts a caller-provided cpu argument. The function uses cpu for per-cpu rstat lookups without checking whether it refers to a valid possible CPU. A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu == 0x7fffffff triggers: UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9 index 2147483647 is out of range for type 'long unsigned int [64]' Call Trace: css_rstat_updated bpf_iter_run_prog cgroup_iter_seq_show bpf_seq_read Add cpu validation to the BPF-facing css_rstat_updated() kfunc and move the common implementation to __css_rstat_updated() for in-kernel callers.

Severity

7.8 (High)


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

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/6a01413a4e8fcb026…
https://git.kernel.org/stable/c/fd2bd9fa7700ddf28…
https://git.kernel.org/stable/c/8817005efbdfdf5d4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a319185be9f5ad13c2a296d448ac52ffe45d194c , < 6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6 (git) Affected: a319185be9f5ad13c2a296d448ac52ffe45d194c , < fd2bd9fa7700ddf28296486b2598cff2f80cc819 (git) Affected: a319185be9f5ad13c2a296d448ac52ffe45d194c , < 8817005efbdfdf5d4e4814cb5dc52b53d12917d7 (git)
Linux	Linux	Affected: 6.1 Unaffected: 0 , < 6.1 (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "block/blk-cgroup.c",
            "include/linux/cgroup.h",
            "kernel/cgroup/rstat.c",
            "mm/memcontrol.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
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              "status": "affected",
              "version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
              "versionType": "git"
            },
            {
              "lessThan": "fd2bd9fa7700ddf28296486b2598cff2f80cc819",
              "status": "affected",
              "version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
              "versionType": "git"
            },
            {
              "lessThan": "8817005efbdfdf5d4e4814cb5dc52b53d12917d7",
              "status": "affected",
              "version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
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          "programFiles": [
            "block/blk-cgroup.c",
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            "mm/memcontrol.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "lessThan": "6.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
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              "versionType": "original_commit_for_fix"
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      ],
      "cpeApplicability": [
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              "cpeMatch": [
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                }
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/rstat: validate cpu before css_rstat_cpu() access\n\ncss_rstat_updated() is exposed as a BPF kfunc and accepts a\ncaller-provided cpu argument. The function uses cpu for per-cpu rstat\nlookups without checking whether it refers to a valid possible CPU.\n\nA BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an\ninvalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==\n0x7fffffff triggers:\n\n  UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9\n  index 2147483647 is out of range for type \u0027long unsigned int [64]\u0027\n  Call Trace:\n    css_rstat_updated\n    bpf_iter_run_prog\n    cgroup_iter_seq_show\n    bpf_seq_read\n\nAdd cpu validation to the BPF-facing css_rstat_updated() kfunc and\nmove the common implementation to __css_rstat_updated() for in-kernel\ncallers."
        }
      ],
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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        "dateUpdated": "2026-07-20T13:42:39.799Z",
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        {
          "url": "https://git.kernel.org/stable/c/8817005efbdfdf5d4e4814cb5dc52b53d12917d7"
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    "datePublished": "2026-07-19T15:39:24.783Z",
    "dateReserved": "2026-07-19T07:54:57.028Z",
    "dateUpdated": "2026-07-20T13:42:39.799Z",
    "state": "PUBLISHED"
  },
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}

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.

Action not permitted

GHSA-7CQC-FVGJ-QM9H

CVE-2026-64036 (GCVE-0-2026-64036)

Tags

Sightings

Nomenclature