CVE-2026-98026 (GCVE-0-2026-98026)

Vulnerability from cvelistv5 – Published: 2026-09-25 10:23 – Updated: 2026-09-25 10:23
VLAI
Title
net: bridge: mcast: properly convert mglist to rcu
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use RCU_INIT_POINTER because we have a barrier from the hlist_add_head_rcu call later, besides we're initializing an unpublished structure anyway.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
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 , < 98247c8264d2076f81fa114bdfa2c2271953ac7c (git)
Affected: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 , < 38ab2a435001a3c4dbeb70a52f5921e1ccd66f55 (git)
Affected: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 , < f7bf57e94a5d6214b87be08486cb33836fbfa573 (git)
Affected: 07f8ac4a1e26e8283542cdaf658a6e2a12fd6980 , < 4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0 (git)
guessed Create a notification for this product.
Linux Linux Affected: 3.16
Unaffected: 0 , < 3.16 (semver)
Unaffected: 6.12.111 , ≤ 6.12.* (semver)
Unaffected: 6.18.53 , ≤ 6.18.* (semver)
Unaffected: 7.2.7 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bridge/br_multicast.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "98247c8264d2076f81fa114bdfa2c2271953ac7c",
              "status": "affected",
              "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
              "versionType": "git"
            },
            {
              "lessThan": "38ab2a435001a3c4dbeb70a52f5921e1ccd66f55",
              "status": "affected",
              "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
              "versionType": "git"
            },
            {
              "lessThan": "f7bf57e94a5d6214b87be08486cb33836fbfa573",
              "status": "affected",
              "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
              "versionType": "git"
            },
            {
              "lessThan": "4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0",
              "status": "affected",
              "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bridge/br_multicast.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.16"
            },
            {
              "lessThan": "3.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.7",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc3",
                  "versionStartIncluding": "3.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-25T10:23:44.505Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/98247c8264d2076f81fa114bdfa2c2271953ac7c"
        },
        {
          "url": "https://git.kernel.org/stable/c/38ab2a435001a3c4dbeb70a52f5921e1ccd66f55"
        },
        {
          "url": "https://git.kernel.org/stable/c/f7bf57e94a5d6214b87be08486cb33836fbfa573"
        },
        {
          "url": "https://git.kernel.org/stable/c/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0"
        }
      ],
      "title": "net: bridge: mcast: properly convert mglist to rcu",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98026",
    "datePublished": "2026-09-25T10:23:44.505Z",
    "dateReserved": "2026-09-25T10:19:56.070Z",
    "dateUpdated": "2026-09-25T10:23:44.505Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "net/bridge/br_multicast.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "98247c8264d2076f81fa114bdfa2c2271953ac7c",
                    "status": "affected",
                    "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "38ab2a435001a3c4dbeb70a52f5921e1ccd66f55",
                    "status": "affected",
                    "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "f7bf57e94a5d6214b87be08486cb33836fbfa573",
                    "status": "affected",
                    "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0",
                    "status": "affected",
                    "version": "07f8ac4a1e26e8283542cdaf658a6e2a12fd6980",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "net/bridge/br_multicast.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "3.16"
                  },
                  {
                    "lessThan": "3.16",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.111",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.53",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.7",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3-rc3",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "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"
          }
        ],
        "id": "CVE-2026-98026",
        "lastModified": "2026-09-25T11:17:31.230",
        "metrics": {},
        "published": "2026-09-25T11:17:31.230",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/38ab2a435001a3c4dbeb70a52f5921e1ccd66f55"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/4b772869a1e5f9da5cef5b9c722ec0aa424ee0a0"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/98247c8264d2076f81fa114bdfa2c2271953ac7c"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/f7bf57e94a5d6214b87be08486cb33836fbfa573"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.