CVE-2025-71080 (GCVE-0-2025-71080)

Vulnerability from cvelistv5 – Published: 2026-01-13 15:34 – Updated: 2026-02-09 08:34
VLAI?
Title
ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT
Summary
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the current task can be preempted. Another task running on the same CPU may then execute rt6_make_pcpu_route() and successfully install a pcpu_rt entry. When the first task resumes execution, its cmpxchg() in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding mdelay() after rt6_get_pcpu_route(). Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep. Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT: free our allocation and return the existing pcpu_rt installed by another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT kernels where such races should not occur.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: d2d6422f8bd17c6bb205133e290625a564194496 , < 1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66 (git)
Affected: d2d6422f8bd17c6bb205133e290625a564194496 , < 787515ccb2292f82eb0876993129154629a49651 (git)
Affected: d2d6422f8bd17c6bb205133e290625a564194496 , < 1adaea51c61b52e24e7ab38f7d3eba023b2d050d (git)
Create a notification for this product.
    Linux Linux Affected: 6.12
Unaffected: 0 , < 6.12 (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/ipv6/route.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66",
              "status": "affected",
              "version": "d2d6422f8bd17c6bb205133e290625a564194496",
              "versionType": "git"
            },
            {
              "lessThan": "787515ccb2292f82eb0876993129154629a49651",
              "status": "affected",
              "version": "d2d6422f8bd17c6bb205133e290625a564194496",
              "versionType": "git"
            },
            {
              "lessThan": "1adaea51c61b52e24e7ab38f7d3eba023b2d050d",
              "status": "affected",
              "version": "d2d6422f8bd17c6bb205133e290625a564194496",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/route.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "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": "6.12.64",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.4",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT\n\nOn PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the\ncurrent task can be preempted. Another task running on the same CPU\nmay then execute rt6_make_pcpu_route() and successfully install a\npcpu_rt entry. When the first task resumes execution, its cmpxchg()\nin rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer\nNULL, triggering the BUG_ON(prev). It\u0027s easy to reproduce it by adding\nmdelay() after rt6_get_pcpu_route().\n\nUsing preempt_disable/enable is not appropriate here because\nip6_rt_pcpu_alloc() may sleep.\n\nFix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:\nfree our allocation and return the existing pcpu_rt installed by\nanother task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT\nkernels where such races should not occur."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-09T08:34:31.425Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66"
        },
        {
          "url": "https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651"
        },
        {
          "url": "https://git.kernel.org/stable/c/1adaea51c61b52e24e7ab38f7d3eba023b2d050d"
        }
      ],
      "title": "ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-71080",
    "datePublished": "2026-01-13T15:34:44.832Z",
    "dateReserved": "2026-01-13T15:30:19.648Z",
    "dateUpdated": "2026-02-09T08:34:31.425Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-71080\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-01-13T16:16:07.550\",\"lastModified\":\"2026-03-25T19:42:22.610\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT\\n\\nOn PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the\\ncurrent task can be preempted. Another task running on the same CPU\\nmay then execute rt6_make_pcpu_route() and successfully install a\\npcpu_rt entry. When the first task resumes execution, its cmpxchg()\\nin rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer\\nNULL, triggering the BUG_ON(prev). It\u0027s easy to reproduce it by adding\\nmdelay() after rt6_get_pcpu_route().\\n\\nUsing preempt_disable/enable is not appropriate here because\\nip6_rt_pcpu_alloc() may sleep.\\n\\nFix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:\\nfree our allocation and return the existing pcpu_rt installed by\\nanother task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT\\nkernels where such races should not occur.\"}],\"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\":\"CWE-617\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.12.1\",\"versionEndExcluding\":\"6.12.64\",\"matchCriteriaId\":\"087ADCE7-533D-4BFC-9FB3-A1872B77A2AA\"},{\"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:6.12:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"0E698080-7669-4132-8817-4C674EEBCE54\"},{\"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/1adaea51c61b52e24e7ab38f7d3eba023b2d050d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

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.