{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/folio.c",
            "mm/vmscan.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "007bc1842317bb99f5f6205afede940f951674c2",
              "status": "affected",
              "version": "07a6e9a2c199fed361f528781284d56771d0016f",
              "versionType": "git"
            },
            {
              "lessThan": "0e0ac326c511d514817cc7b6d7741afd59098ce2",
              "status": "affected",
              "version": "07a6e9a2c199fed361f528781284d56771d0016f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "mm/folio.c",
            "mm/vmscan.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmemcg: move LRU size accounting on reparenting instead of copying it\n\nWhen a memory cgroup is offlined its LRU folios are reparented to the\nparent.  lruvec_reparent_lru() splices the child\u0027s lists into the\nparent\u0027s and credits the parent with the child\u0027s per-zone\nlru_zone_size[], but never clears the child\u0027s copy, so the size is\ncopied rather than moved.  lru_gen_reparent_memcg() does the same for\nMGLRU.\n\nThe parent is left correct, credited with exactly the folios it took\nover.  The stale value sits on the child and nothing will correct it:\nfolio-\u003ememcg_data now resolves to the parent, so every later\nupdate_lru_size() for those folios goes there.\n\nDying cgroups are not freed immediately and mem_cgroup_iter() still\nwalks them, so shrink_lruvec() keeps being called on them.\nget_scan_count() reads the phantom counter through lruvec_lru_size() and\nthe scan loop then grinds through nr[] in SWAP_CLUSTER_MAX steps against\nan empty list, for as long as the dead cgroup lives.  Under MGLRU the\nMGLRU scanner runs instead, but count_shadow_nodes() sums all of\nNR_LRU_LISTS through lruvec_lru_size() and over-budgets the shadow node\nlimit just the same.\n\nOn one 251 GiB host a sweep of every mz-\u003elru_zone_size[] found 380\ncounters describing folios on no list at all: 124777314 pages, 476 GiB,\n1.89x the machine\u0027s RAM, across 57 cgroups.  All were on memcgs with\nCSS_DYING set and CSS_ONLINE clear, and parent/child pairs reported\nbyte-identical sizes.\n\nLRU_UNEVICTABLE needs its size moved too.  Its list is deliberately not\nspliced because lruvec_init() poisons the head - the unevictable LRU is\nimaginary and folios are never threaded on it - but the size is kept by\nlruvec_add_folio()/lruvec_del_folio() and those folios account to the\nparent from here on.\n\nThis depends on commit bf4ade7dbd76 (\"memcg: keep folio\u0027s objcg same as\nits node\") and must not be backported ahead of it.  Without that\ninvariant a folio\u0027s objcg can belong to another node, so a folio already\nspliced onto the parent\u0027s list can still resolve to the child\u0027s lruvec\nuntil the objcg\u0027s node is reparented in a later iteration of\nmemcg_reparent_objcgs(); clearing the child\u0027s counter early then lets\nlruvec_del_folio() underflow it and trip the WARN_ONCE()/VM_BUG_ON() in\nmem_cgroup_update_lru_size()."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:07:09.510Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/007bc1842317bb99f5f6205afede940f951674c2"
        },
        {
          "url": "https://git.kernel.org/stable/c/0e0ac326c511d514817cc7b6d7741afd59098ce2"
        }
      ],
      "title": "memcg: move LRU size accounting on reparenting instead of copying it",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-93197",
    "datePublished": "2026-09-17T16:12:19.776Z",
    "dateReserved": "2026-09-17T16:02:15.092Z",
    "dateUpdated": "2026-10-19T09:07:09.510Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}