CVE-2025-71097 (GCVE-0-2025-71097)

Vulnerability from cvelistv5 – Published: 2026-01-13 15:34 – Updated: 2026-05-11 21:54
VLAI
Title
ipv4: Fix reference count leak when using error routes with nexthop objects
Summary
In the Linux kernel, the following vulnerability has been resolved: ipv4: Fix reference count leak when using error routes with nexthop objects When a nexthop object is deleted, it is marked as dead and then fib_table_flush() is called to flush all the routes that are using the dead nexthop. The current logic in fib_table_flush() is to only flush error routes (e.g., blackhole) when it is called as part of network namespace dismantle (i.e., with flush_all=true). Therefore, error routes are not flushed when their nexthop object is deleted: # ip link add name dummy1 up type dummy # ip nexthop add id 1 dev dummy1 # ip route add 198.51.100.1/32 nhid 1 # ip route add blackhole 198.51.100.2/32 nhid 1 # ip nexthop del id 1 # ip route show blackhole 198.51.100.2 nhid 1 dev dummy1 As such, they keep holding a reference on the nexthop object which in turn holds a reference on the nexthop device, resulting in a reference count leak: # ip link del dev dummy1 [ 70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2 Fix by flushing error routes when their nexthop is marked as dead. IPv6 does not suffer from this problem.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < 5de7ad7e18356e39e8fbf7edd185a5faaf4f385a (git)
Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < 33ff5c207c873215e54e6176624ed57423cb7dea (git)
Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < 30386e090c49e803c0616a7147e43409c32a2b0e (git)
Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < 5979338c83012110ccd45cae6517591770bfe536 (git)
Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < ee4183501ea556dca31f5ffd8690aa9fd25b609f (git)
Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < e3fc381320d04e4a74311e576a86cac49a16fc43 (git)
Affected: 493ced1ac47c48bb86d9d4e8e87df8592be85a0e , < ac782f4e3bfcde145b8a7f8af31d9422d94d172a (git)
Create a notification for this product.
Linux Linux Affected: 5.3
Unaffected: 0 , < 5.3 (semver)
Unaffected: 5.10.248 , ≤ 5.10.* (semver)
Unaffected: 5.15.198 , ≤ 5.15.* (semver)
Unaffected: 6.1.160 , ≤ 6.1.* (semver)
Unaffected: 6.6.120 , ≤ 6.6.* (semver)
Unaffected: 6.12.64 , ≤ 6.12.* (semver)
Unaffected: 6.18.4 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/fib_trie.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5de7ad7e18356e39e8fbf7edd185a5faaf4f385a",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            },
            {
              "lessThan": "33ff5c207c873215e54e6176624ed57423cb7dea",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            },
            {
              "lessThan": "30386e090c49e803c0616a7147e43409c32a2b0e",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            },
            {
              "lessThan": "5979338c83012110ccd45cae6517591770bfe536",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            },
            {
              "lessThan": "ee4183501ea556dca31f5ffd8690aa9fd25b609f",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            },
            {
              "lessThan": "e3fc381320d04e4a74311e576a86cac49a16fc43",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            },
            {
              "lessThan": "ac782f4e3bfcde145b8a7f8af31d9422d94d172a",
              "status": "affected",
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/fib_trie.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "lessThan": "5.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.248",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.198",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.120",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.64",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.248",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.198",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.160",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.120",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.64",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.4",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: Fix reference count leak when using error routes with nexthop objects\n\nWhen a nexthop object is deleted, it is marked as dead and then\nfib_table_flush() is called to flush all the routes that are using the\ndead nexthop.\n\nThe current logic in fib_table_flush() is to only flush error routes\n(e.g., blackhole) when it is called as part of network namespace\ndismantle (i.e., with flush_all=true). Therefore, error routes are not\nflushed when their nexthop object is deleted:\n\n # ip link add name dummy1 up type dummy\n # ip nexthop add id 1 dev dummy1\n # ip route add 198.51.100.1/32 nhid 1\n # ip route add blackhole 198.51.100.2/32 nhid 1\n # ip nexthop del id 1\n # ip route show\n blackhole 198.51.100.2 nhid 1 dev dummy1\n\nAs such, they keep holding a reference on the nexthop object which in\nturn holds a reference on the nexthop device, resulting in a reference\ncount leak:\n\n # ip link del dev dummy1\n [   70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2\n\nFix by flushing error routes when their nexthop is marked as dead.\n\nIPv6 does not suffer from this problem."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:54:41.289Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5de7ad7e18356e39e8fbf7edd185a5faaf4f385a"
        },
        {
          "url": "https://git.kernel.org/stable/c/33ff5c207c873215e54e6176624ed57423cb7dea"
        },
        {
          "url": "https://git.kernel.org/stable/c/30386e090c49e803c0616a7147e43409c32a2b0e"
        },
        {
          "url": "https://git.kernel.org/stable/c/5979338c83012110ccd45cae6517591770bfe536"
        },
        {
          "url": "https://git.kernel.org/stable/c/ee4183501ea556dca31f5ffd8690aa9fd25b609f"
        },
        {
          "url": "https://git.kernel.org/stable/c/e3fc381320d04e4a74311e576a86cac49a16fc43"
        },
        {
          "url": "https://git.kernel.org/stable/c/ac782f4e3bfcde145b8a7f8af31d9422d94d172a"
        }
      ],
      "title": "ipv4: Fix reference count leak when using error routes with nexthop objects",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-71097",
    "datePublished": "2026-01-13T15:34:56.814Z",
    "dateReserved": "2026-01-13T15:30:19.650Z",
    "dateUpdated": "2026-05-11T21:54:41.289Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-71097",
      "date": "2026-05-27",
      "epss": "0.00033",
      "percentile": "0.09872"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-71097\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-01-13T16:16:09.583\",\"lastModified\":\"2026-03-25T16:56:30.463\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nipv4: Fix reference count leak when using error routes with nexthop objects\\n\\nWhen a nexthop object is deleted, it is marked as dead and then\\nfib_table_flush() is called to flush all the routes that are using the\\ndead nexthop.\\n\\nThe current logic in fib_table_flush() is to only flush error routes\\n(e.g., blackhole) when it is called as part of network namespace\\ndismantle (i.e., with flush_all=true). Therefore, error routes are not\\nflushed when their nexthop object is deleted:\\n\\n # ip link add name dummy1 up type dummy\\n # ip nexthop add id 1 dev dummy1\\n # ip route add 198.51.100.1/32 nhid 1\\n # ip route add blackhole 198.51.100.2/32 nhid 1\\n # ip nexthop del id 1\\n # ip route show\\n blackhole 198.51.100.2 nhid 1 dev dummy1\\n\\nAs such, they keep holding a reference on the nexthop object which in\\nturn holds a reference on the nexthop device, resulting in a reference\\ncount leak:\\n\\n # ip link del dev dummy1\\n [   70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2\\n\\nFix by flushing error routes when their nexthop is marked as dead.\\n\\nIPv6 does not suffer from this problem.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-Other\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.3.1\",\"versionEndExcluding\":\"5.10.248\",\"matchCriteriaId\":\"FC0F2CC0-B58E-4871-8AFA-7E45B21DE3EE\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.11\",\"versionEndExcluding\":\"5.15.198\",\"matchCriteriaId\":\"82159CAA-B6BA-43C6-85D8-65BDBC175A7E\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.16\",\"versionEndExcluding\":\"6.1.160\",\"matchCriteriaId\":\"C10CC03E-16A9-428A-B449-40D3763E15F6\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.6.120\",\"matchCriteriaId\":\"43C3A206-5EEE-417B-AA0F-EF8972E7A9F0\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.7\",\"versionEndExcluding\":\"6.12.64\",\"matchCriteriaId\":\"32BF4A52-377C-44ED-B5E6-7EA5D896E98B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.18.4\",\"matchCriteriaId\":\"DC988EA0-0E32-457A-BF95-89BEB31A227B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:5.3:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"D036D76E-AC69-4382-B4C1-8EDA1ABB2941\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"17B67AA7-40D6-4AFA-8459-F200F3D7CFD1\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"C47E4CC9-C826-4FA9-B014-7FE3D9B318B2\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"F71D92C0-C023-48BD-B3B6-70B638EEE298\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*\",\"matchCriteriaId\":\"13580667-0A98-40CC-B29F-D12790B91BDB\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*\",\"matchCriteriaId\":\"CAD1FED7-CF48-47BF-AC7D-7B6FA3C065FC\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*\",\"matchCriteriaId\":\"3EF854A1-ABB1-4E93-BE9A-44569EC76C0D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:*\",\"matchCriteriaId\":\"F5DC0CA6-F0AF-4DDF-A882-3DADB9A886A7\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:*\",\"matchCriteriaId\":\"EB5B7DFC-C36B-45D8-922C-877569FDDF43\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/30386e090c49e803c0616a7147e43409c32a2b0e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/33ff5c207c873215e54e6176624ed57423cb7dea\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5979338c83012110ccd45cae6517591770bfe536\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5de7ad7e18356e39e8fbf7edd185a5faaf4f385a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/ac782f4e3bfcde145b8a7f8af31d9422d94d172a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/e3fc381320d04e4a74311e576a86cac49a16fc43\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/ee4183501ea556dca31f5ffd8690aa9fd25b609f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}"
  }
}


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.



Detection rules are retrieved from Rulezet.