UnratedFix available

ipmr: account multicast table and route memory

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: ipmr: account multicast table and route memory A netadmin in a user+net namespace can create many IPv4 and IPv6 multicast routing tables with MRT_TABLE and MRT6_TABLE. Each unseen id allocates an mr_table via the shared mr_table_alloc(), links it into the per-net list, and leaves it until netns teardown. Those objects were not charged to memcg, so the host unreclaimable slab grows with the table count. Account mr_table allocations with GFP_KERNEL_ACCOUNT and mark the IPv4/IPv6 MFC caches SLAB_ACCOUNT. This matches the established handling of IP addresses, routes and alternate interface names. Unresolved MFC entries are still allocated from softIRQ with GFP_ATOMIC and are not charged. They expire after 10 seconds and are bounded by the socket receive queue; see commit 0079ad8e8dc3 ("ipmr: remove hard code cache_resolve_queue_len limit").

Products: Kernel
Affected versions: Not specified
Fixed versions: 5.10.273, 5.15.224, 6.1.191, 6.12.112, 6.18.53, 6.6.160, 7.2.7
CVEs: CVE-2026-97939
Confirmed fixed CVEs: Not specified
Updated in this feed: 3 Nov 2026, 17:10 UTC · Revision 1

Source evidence

ipmr: account multicast table and route memory

core-osv · Original source

Published 25 Sept 2026, 10:22 UTC

osv:CVE-2026-97939

Kernel

Fixed versions: 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.112, 6.18.53, 7.2.7

Complete source record

{
  "id": "dccbe489643d2de59f31ed4cfce728d5b4b38017041e0b763ee534377e3c9b5b",
  "url": "https://osv.dev/vulnerability/CVE-2026-97939",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ipmr: account multicast table and route memory",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ipmr: account multicast table and route memory A netadmin in a user+net namespace can create many IPv4 and IPv6 multicast routing tables with MRT_TABLE and MRT6_TABLE. Each unseen id allocates an mr_table via the shared mr_table_alloc(), links it into the per-net list, and leaves it until netns teardown. Those objects were not charged to memcg, so the host unreclaimable slab grows with the table count. Account mr_table allocations with GFP_KERNEL_ACCOUNT and mark the IPv4/IPv6 MFC caches SLAB_ACCOUNT. This matches the established handling of IP addresses, routes and alternate interface names. Unresolved MFC entries are still allocated from softIRQ with GFP_ATOMIC and are not charged. They expire after 10 seconds and are bounded by the socket receive queue; see commit 0079ad8e8dc3 (\"ipmr: remove hard code cache_resolve_queue_len limit\").",
    "evidence": "osv:CVE-2026-97939",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.273",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.224",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.191",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.160",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.112",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.53",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.7",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-97939",
      "aliases": [
        "CVE-2026-97939"
      ],
      "affected": [
        {
          "ranges": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                },
                {
                  "fixed": "57c523e95ea2608a19e6bfcd664d641ddf7bc4b4"
                },
                {
                  "fixed": "20424f267c9dbdfcade28b2b2306767a7dfb43d1"
                },
                {
                  "fixed": "21e0749e8ef272ac7e3eefe0fa488a5983f4b038"
                },
                {
                  "fixed": "ec1c6140394ee87127479bc500a3158b125bf07a"
                },
                {
                  "fixed": "0264b3ee09b118fec8a5471b4ca288f8ab84722f"
                },
                {
                  "fixed": "d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c"
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                {
                  "fixed": "b7ee18725f2292ab554aa96a101ae42d45f008bd"
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          "database_specific": {
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          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "2.6.35"
                },
                {
                  "fixed": "5.10.273"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
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                {
                  "fixed": "5.15.224"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.191"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.160"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
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                {
                  "fixed": "6.12.112"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.53"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.7"
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              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-97939.json"
          }
        }
      ],
      "modified": "2026-11-01T02:30:56.829193494Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0264b3ee09b118fec8a5471b4ca288f8ab84722f",
        "https://git.kernel.org/stable/c/20424f267c9dbdfcade28b2b2306767a7dfb43d1",
        "https://git.kernel.org/stable/c/21e0749e8ef272ac7e3eefe0fa488a5983f4b038",
        "https://git.kernel.org/stable/c/3e808d8dfebd8f114a747bd90c8f7d2a6fd7474f",
        "https://git.kernel.org/stable/c/57c523e95ea2608a19e6bfcd664d641ddf7bc4b4",
        "https://git.kernel.org/stable/c/b7ee18725f2292ab554aa96a101ae42d45f008bd",
        "https://git.kernel.org/stable/c/d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c",
        "https://git.kernel.org/stable/c/ec1c6140394ee87127479bc500a3158b125bf07a",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97939.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-97939",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97939.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-97939",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 497708,
  "published_at": "2026-09-25T10:22:52.332+00:00"
}