Vulnerability-Lookup

GHSA-CQHP-GWHX-VMWP

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch

In alloc_hugetlb_folio(), a single h_cg pointer is used for both the rsvd and non-rsvd hugetlb cgroup charges. When map_chg is set, hugetlb_cgroup_charge_cgroup_rsvd() stores the charged cgroup in h_cg, but the immediately following hugetlb_cgroup_charge_cgroup() overwrites h_cg with the non-rsvd cgroup pointer.

As a result, hugetlb_cgroup_commit_charge_rsvd() stores the wrong (non-rsvd) cgroup pointer into the folio's rsvd slot.

When the folio is later freed, free_huge_folio() unconditionally calls both hugetlb_cgroup_uncharge_folio() and hugetlb_cgroup_uncharge_folio_rsvd(). The rsvd uncharge reads back the wrong cgroup from the folio and decrements a counter that was never charged for that cgroup, causing a page_counter underflow:

page_counter underflow: -512 nr_pages=512 WARNING: mm/page_counter.c:61 at page_counter_cancel

Fix this by introducing a separate h_cg_rsvd pointer exclusively for the rsvd charge path, keeping the rsvd and non-rsvd charges fully independent through their charge, commit, and error uncharge paths.

Severity

7.1 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-72213"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:21:40Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch\n\nIn alloc_hugetlb_folio(), a single h_cg pointer is used for both the rsvd\nand non-rsvd hugetlb cgroup charges.  When map_chg is set,\nhugetlb_cgroup_charge_cgroup_rsvd() stores the charged cgroup in h_cg, but\nthe immediately following hugetlb_cgroup_charge_cgroup() overwrites h_cg\nwith the non-rsvd cgroup pointer.\n\nAs a result, hugetlb_cgroup_commit_charge_rsvd() stores the wrong\n(non-rsvd) cgroup pointer into the folio\u0027s rsvd slot.\n\nWhen the folio is later freed, free_huge_folio() unconditionally calls\nboth hugetlb_cgroup_uncharge_folio() and\nhugetlb_cgroup_uncharge_folio_rsvd().  The rsvd uncharge reads back the\nwrong cgroup from the folio and decrements a counter that was never\ncharged for that cgroup, causing a page_counter underflow:\n\n  page_counter underflow: -512 nr_pages=512\n  WARNING: mm/page_counter.c:61 at page_counter_cancel\n\nFix this by introducing a separate h_cg_rsvd pointer exclusively for the\nrsvd charge path, keeping the rsvd and non-rsvd charges fully independent\nthrough their charge, commit, and error uncharge paths.",
  "id": "GHSA-cqhp-gwhx-vmwp",
  "modified": "2026-08-17T06:33:16Z",
  "published": "2026-08-15T06:32:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72213"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/15807d0ddde37407af72859426b654f3d1972b00"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1697d253f51cf5e3825a3423ff49e128a3502ab2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5c32ae4a91fb5f4941328e0c1720a7fa4189c3bd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b785f2bd9496facedc0a031be09cddcd1d3c84d3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-72213 (GCVE-0-2026-72213)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:54 – Updated: 2026-08-17 05:41

Title

mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch In alloc_hugetlb_folio(), a single h_cg pointer is used for both the rsvd and non-rsvd hugetlb cgroup charges. When map_chg is set, hugetlb_cgroup_charge_cgroup_rsvd() stores the charged cgroup in h_cg, but the immediately following hugetlb_cgroup_charge_cgroup() overwrites h_cg with the non-rsvd cgroup pointer. As a result, hugetlb_cgroup_commit_charge_rsvd() stores the wrong (non-rsvd) cgroup pointer into the folio's rsvd slot. When the folio is later freed, free_huge_folio() unconditionally calls both hugetlb_cgroup_uncharge_folio() and hugetlb_cgroup_uncharge_folio_rsvd(). The rsvd uncharge reads back the wrong cgroup from the folio and decrements a counter that was never charged for that cgroup, causing a page_counter underflow: page_counter underflow: -512 nr_pages=512 WARNING: mm/page_counter.c:61 at page_counter_cancel Fix this by introducing a separate h_cg_rsvd pointer exclusively for the rsvd charge path, keeping the rsvd and non-rsvd charges fully independent through their charge, commit, and error uncharge paths.

Severity

7.1 (High)


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

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/5c32ae4a91fb5f494…
https://git.kernel.org/stable/c/1697d253f51cf5e38…
https://git.kernel.org/stable/c/b785f2bd9496faced…
https://git.kernel.org/stable/c/15807d0ddde37407a…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 08cf9faf7558020aed6a0da5810b824b07139dfa , < 5c32ae4a91fb5f4941328e0c1720a7fa4189c3bd (git) Affected: 08cf9faf7558020aed6a0da5810b824b07139dfa , < 1697d253f51cf5e3825a3423ff49e128a3502ab2 (git) Affected: 08cf9faf7558020aed6a0da5810b824b07139dfa , < b785f2bd9496facedc0a031be09cddcd1d3c84d3 (git) Affected: 08cf9faf7558020aed6a0da5810b824b07139dfa , < 15807d0ddde37407af72859426b654f3d1972b00 (git)
Linux	Linux	Affected: 5.7 Unaffected: 0 , < 5.7 (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
            "mm/hugetlb.c"
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              "versionType": "git"
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              "status": "unaffected",
              "version": "0",
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              "versionType": "semver"
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      "cpeApplicability": [
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          "nodes": [
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                  "versionStartIncluding": "5.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
                {
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                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch\n\nIn alloc_hugetlb_folio(), a single h_cg pointer is used for both the rsvd\nand non-rsvd hugetlb cgroup charges.  When map_chg is set,\nhugetlb_cgroup_charge_cgroup_rsvd() stores the charged cgroup in h_cg, but\nthe immediately following hugetlb_cgroup_charge_cgroup() overwrites h_cg\nwith the non-rsvd cgroup pointer.\n\nAs a result, hugetlb_cgroup_commit_charge_rsvd() stores the wrong\n(non-rsvd) cgroup pointer into the folio\u0027s rsvd slot.\n\nWhen the folio is later freed, free_huge_folio() unconditionally calls\nboth hugetlb_cgroup_uncharge_folio() and\nhugetlb_cgroup_uncharge_folio_rsvd().  The rsvd uncharge reads back the\nwrong cgroup from the folio and decrements a counter that was never\ncharged for that cgroup, causing a page_counter underflow:\n\n  page_counter underflow: -512 nr_pages=512\n  WARNING: mm/page_counter.c:61 at page_counter_cancel\n\nFix this by introducing a separate h_cg_rsvd pointer exclusively for the\nrsvd charge path, keeping the rsvd and non-rsvd charges fully independent\nthrough their charge, commit, and error uncharge paths."
        }
      ],
      "metrics": [
        {
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            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          },
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            {
              "lang": "en",
              "value": "AV:L - The bug is in alloc_hugetlb_folio()/free_huge_folio() and is reached only via local MM paths (mmap/munmap, hugetlb page faults, fallocate, memfd MFD_HUGETLB, MAP_HUGETLB) that syzbot triggered through hugetlbfs inode eviction, not via any network-facing kernel service.\nAC:L - An unprivileged attacker can reliably trigger the mismatch by creating hugetlbfs mappings without reservations (MAP_NORESERVE or fault-before-reserve), faulting in huge pages to run alloc_hugetlb_folio() with map_chg set, then closing/unmapping to free folios and hit the bad rsvd uncharge.\nPR:L - Triggering requires only an unprivileged local process that can use hugetlb memory (hugetlbfs/MAP_HUGETLB/memfd) under a hugetlb cgroup; no init-namespace root or special driver capabilities are needed, and cgroup hugetlb limits are controllable from user namespaces.\nUI:N - Exploitation is fully attacker-driven through normal syscalls (mmap, write/fault, close/unlink) and does not require any victim user action beyond the attacker operating on their own mappings.\nS:U - Impact is confined to kernel hugetlb/cgroup page_counter accounting within the same host kernel security domain; it does not cross VM, container runtime, or IOMMU boundaries.\nC:N - The flaw corrupts hugetlb cgroup reservation counters and emits a WARN on underflow; it does not read or disclose kernel memory, pointers, or other confidential data to the attacker.\nI:H - page_counter underflow forcibly resets hugetlb cgroup reservation usage to zero, corrupting kernel accounting so an attacker can bypass hugetlb.rsvd cgroup limits and consume hugepage resources beyond enforced quotas in multi-tenant/container deployments.\nA:H - free_huge_folio() unconditionally hits the bad rsvd uncharge and triggers a kernel WARNING/page_counter underflow during hugepage teardown; syzbot classified this as DoS and repeated alloc/free cycles can disrupt hugetlb availability for other workloads when limits are bypassed."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:41:39.361Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/5c32ae4a91fb5f4941328e0c1720a7fa4189c3bd"
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          "url": "https://git.kernel.org/stable/c/1697d253f51cf5e3825a3423ff49e128a3502ab2"
        },
        {
          "url": "https://git.kernel.org/stable/c/b785f2bd9496facedc0a031be09cddcd1d3c84d3"
        },
        {
          "url": "https://git.kernel.org/stable/c/15807d0ddde37407af72859426b654f3d1972b00"
        }
      ],
      "title": "mm/hugetlb: fix hugetlb cgroup rsvd charge/uncharge mismatch",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72213",
    "datePublished": "2026-08-15T05:54:07.854Z",
    "dateReserved": "2026-08-09T03:40:39.912Z",
    "dateUpdated": "2026-08-17T05:41:39.361Z",
    "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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-CQHP-GWHX-VMWP

CVE-2026-72213 (GCVE-0-2026-72213)

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Sightings

Nomenclature