CVE-2026-98026 (GCVE-0-2026-98026)
Vulnerability from cvelistv5
Published
2026-09-25 10:23
Modified
2026-10-19 09:12
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: properly convert mglist to rcu Sashiko reported a bug [1] that br_multicast_del_port_group unlists the port group not using proper rcu helper that preserves the next pointer and after that immediately frees the port group without waiting for rcu grace period. The only rcu walker of mglist is br_multicast_list_adjacent() and it turns out that function has always been buggy because mglist was never properly converted to RCU. Fix it by converting it to rcu and moving its initialization after eth_addr's. Initializing p->next can use RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call later, besides we're initializing an unpublished structure anyway. [1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com
References
Impacted products
Vendor Product Version
Linux Linux Version: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980
Version: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980
Version: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980
Version: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980
Version: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980
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{
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          "programFiles": [
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      "cpeApplicability": [
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: mcast: properly convert mglist to rcu\n\nSashiko reported a bug [1] that br_multicast_del_port_group unlists the\nport group not using proper rcu helper that preserves the next pointer and\nafter that immediately frees the port group without waiting for rcu grace\nperiod. The only rcu walker of mglist is br_multicast_list_adjacent() and\nit turns out that function has always been buggy because mglist was never\nproperly converted to RCU. Fix it by converting it to rcu and moving its\ninitialization after eth_addr\u0027s. Initializing p-\u003enext can use\nRCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call\nlater, besides we\u0027re initializing an unpublished structure anyway.\n\n[1] https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260826014200.362304-1-littleddfu%40gmail.com"
        }
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        "dateUpdated": "2026-10-19T09:12:31.334Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/37cb9a81600da8250f24e25edc07253b62353cbe"
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        },
        {
          "url": "https://git.kernel.org/stable/c/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0"
        }
      ],
      "title": "net: bridge: mcast: properly convert mglist to rcu",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98026",
    "datePublished": "2026-09-25T10:23:44.505Z",
    "dateReserved": "2026-09-25T10:19:56.070Z",
    "dateUpdated": "2026-10-19T09:12:31.334Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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