CVE-2026-93216 (GCVE-0-2026-93216)

Vulnerability from cvelistv5 – Published: 2026-09-24 15:10 – Updated: 2026-09-24 15:10
VLAI
Title
mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()
Summary
In the Linux kernel, the following vulnerability has been resolved: mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg() print_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the start to guard against tail pages and NULL data. However, it later re-reads page->memcg_data locklessly in two places: 1: page_memcg_check(page) 2: PageMemcgKmem(page) (via folio_memcg_kmem(), which includes VM_BUG_ON assertions for tail pages and MEMCG_DATA_OBJEXTS) If the page is concurrently freed and reallocated as a THP tail page or slab page between these calls, the VM_BUG_ON assertions can trigger on CONFIG_DEBUG_VM=y builds, crashing the kernel. Fix both TOCTOU issues by using the memcg_data snapshot throughout.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: fcf8935832b86d3437f00e732c6d0d4d2819d6a9 , < 46761406e14381dc35f498c247a87565b87ea2ef (git)
Affected: fcf8935832b86d3437f00e732c6d0d4d2819d6a9 , < 90f095b816e25c6a9e4446d299bac5007fdcb3df (git)
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Linux Linux Affected: 5.18
Unaffected: 0 , < 5.18 (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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          "product": "Linux",
          "programFiles": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()\n\nprint_page_owner_memcg() reads page-\u003ememcg_data via READ_ONCE() at the\nstart to guard against tail pages and NULL data.  However, it later\nre-reads page-\u003ememcg_data locklessly in two places:\n\n1: page_memcg_check(page)\n\n2: PageMemcgKmem(page) (via folio_memcg_kmem(), which includes\n   VM_BUG_ON assertions for tail pages and MEMCG_DATA_OBJEXTS)\n\nIf the page is concurrently freed and reallocated as a THP tail page or\nslab page between these calls, the VM_BUG_ON assertions can trigger on\nCONFIG_DEBUG_VM=y builds, crashing the kernel.\n\nFix both TOCTOU issues by using the memcg_data snapshot throughout."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-24T15:10:38.702Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        }
      ],
      "title": "mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()",
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    "cveId": "CVE-2026-93216",
    "datePublished": "2026-09-24T15:10:38.702Z",
    "dateReserved": "2026-09-17T16:02:15.093Z",
    "dateUpdated": "2026-09-24T15:10:38.702Z",
    "state": "PUBLISHED"
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      "source": "Microsoft CSAF VEX",
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      "title": "mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-93216.json",
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        "descriptions": [
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            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()\n\nprint_page_owner_memcg() reads page-\u003ememcg_data via READ_ONCE() at the\nstart to guard against tail pages and NULL data.  However, it later\nre-reads page-\u003ememcg_data locklessly in two places:\n\n1: page_memcg_check(page)\n\n2: PageMemcgKmem(page) (via folio_memcg_kmem(), which includes\n   VM_BUG_ON assertions for tail pages and MEMCG_DATA_OBJEXTS)\n\nIf the page is concurrently freed and reallocated as a THP tail page or\nslab page between these calls, the VM_BUG_ON assertions can trigger on\nCONFIG_DEBUG_VM=y builds, crashing the kernel.\n\nFix both TOCTOU issues by using the memcg_data snapshot throughout."
          }
        ],
        "id": "CVE-2026-93216",
        "lastModified": "2026-09-24T16:17:16.670",
        "metrics": {},
        "published": "2026-09-24T16:17:16.670",
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        "vulnStatus": "Received"
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      "cve": "CVE-2026-93216",
      "id": "CVE-2026-93216",
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      "product_status:known_affected": "108",
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      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-93216",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-93216.json",
      "version": "3"
    }
  }
}



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