Vulnerability-Lookup

GHSA-G6RX-F8GV-C53J

Vulnerability from github – Published: 2026-08-05 09:31 – Updated: 2026-08-08 15:30

Details

In the Linux kernel, the following vulnerability has been resolved:

xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()

On the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst() releases the device reference with netdev_put() but leaves xdst->u.dst.dev set. dst_destroy() later calls netdev_put(dst->dev) again, so the same net_device reference is released twice, underflowing its refcount (ref_tracker WARNING + "unregister_netdevice: waiting for to become free").

Clear xdst->u.dst.dev after the netdev_put(), the same way the XFRM device-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in net/xfrm/xfrm_device.c NULL ->dev when releasing the reference on error.

ref_tracker: reference already released. ref_tracker: allocated in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86) ... udpv6_sendmsg (net/ipv6/udp.c:1696) ... ref_tracker: freed in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90) ... WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780 dst_destroy (net/core/dst.c:115) rcu_core handle_softirqs ...

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64580"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T08:16:38Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()\n\nOn the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst()\nreleases the device reference with netdev_put() but leaves\nxdst-\u003eu.dst.dev set. dst_destroy() later calls netdev_put(dst-\u003edev)\nagain, so the same net_device reference is released twice, underflowing\nits refcount (ref_tracker WARNING + \"unregister_netdevice: waiting for\n\u003cdev\u003e to become free\").\n\nClear xdst-\u003eu.dst.dev after the netdev_put(), the same way the XFRM\ndevice-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in\nnet/xfrm/xfrm_device.c NULL -\u003edev when releasing the reference on error.\n\n  ref_tracker: reference already released.\n  ref_tracker: allocated in:\n   xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86)\n   ...\n   udpv6_sendmsg (net/ipv6/udp.c:1696)\n   ...\n  ref_tracker: freed in:\n   xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90)\n   ...\n  WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780\n   dst_destroy (net/core/dst.c:115)\n   rcu_core\n   handle_softirqs\n   ...",
  "id": "GHSA-g6rx-f8gv-c53j",
  "modified": "2026-08-08T15:30:25Z",
  "published": "2026-08-05T09:31:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64580"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/136992de9bb91871084ae52d172610541c76e4d2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/43de8a49335e611adb271bbd52e84dfbc11fc185"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/df6856c2dda9187601d29b5fbd7a81b3b178cedf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e078da1b4e11390cff3201c19a9a1fe70c5b934f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff636d7b7cba6dea82ecf580415ea57f2c1a11b6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64580 (GCVE-0-2026-64580)

Vulnerability from cvelistv5 – Published: 2026-08-05 08:09 – Updated: 2026-08-08 15:13

Title

xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()

Summary

In the Linux kernel, the following vulnerability has been resolved: xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst() On the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst() releases the device reference with netdev_put() but leaves xdst->u.dst.dev set. dst_destroy() later calls netdev_put(dst->dev) again, so the same net_device reference is released twice, underflowing its refcount (ref_tracker WARNING + "unregister_netdevice: waiting for <dev> to become free"). Clear xdst->u.dst.dev after the netdev_put(), the same way the XFRM device-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in net/xfrm/xfrm_device.c NULL ->dev when releasing the reference on error. ref_tracker: reference already released. ref_tracker: allocated in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86) ... udpv6_sendmsg (net/ipv6/udp.c:1696) ... ref_tracker: freed in: xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90) ... WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780 dst_destroy (net/core/dst.c:115) rcu_core handle_softirqs ...

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/df6856c2dda918760…
https://git.kernel.org/stable/c/43de8a49335e611ad…
https://git.kernel.org/stable/c/ff636d7b7cba6dea8…
https://git.kernel.org/stable/c/e078da1b4e11390cf…
https://git.kernel.org/stable/c/136992de9bb918710…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 84c4a9dfbf430861e7588d95ae3ff61535dca351 , < df6856c2dda9187601d29b5fbd7a81b3b178cedf (git) Affected: 84c4a9dfbf430861e7588d95ae3ff61535dca351 , < 43de8a49335e611adb271bbd52e84dfbc11fc185 (git) Affected: 84c4a9dfbf430861e7588d95ae3ff61535dca351 , < ff636d7b7cba6dea82ecf580415ea57f2c1a11b6 (git) Affected: 84c4a9dfbf430861e7588d95ae3ff61535dca351 , < e078da1b4e11390cff3201c19a9a1fe70c5b934f (git) Affected: 84c4a9dfbf430861e7588d95ae3ff61535dca351 , < 136992de9bb91871084ae52d172610541c76e4d2 (git) Affected: a7e22d0c0e81dde129a51ee413644124f4b59954 (git) Affected: 01b0d887f67a388fb2a658ee2bdd74e5ba146818 (git) Affected: a98124aac0b5adc5de8ae54f11322781cb4d85c3 (git) Affected: e27b7bee743d921f037b1da6f071237345bef7c1 (git) Affected: 3.0.79 , < 3.1 (semver) Affected: 3.2.46 , < 3.3 (semver) Affected: 3.4.46 , < 3.5 (semver) Affected: 3.9.3 , < 3.10 (semver)
Linux	Linux	Affected: 3.10 Unaffected: 0 , < 3.10 (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2-rc4 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/xfrm6_policy.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "df6856c2dda9187601d29b5fbd7a81b3b178cedf",
              "status": "affected",
              "version": "84c4a9dfbf430861e7588d95ae3ff61535dca351",
              "versionType": "git"
            },
            {
              "lessThan": "43de8a49335e611adb271bbd52e84dfbc11fc185",
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              "version": "84c4a9dfbf430861e7588d95ae3ff61535dca351",
              "versionType": "git"
            },
            {
              "lessThan": "ff636d7b7cba6dea82ecf580415ea57f2c1a11b6",
              "status": "affected",
              "version": "84c4a9dfbf430861e7588d95ae3ff61535dca351",
              "versionType": "git"
            },
            {
              "lessThan": "e078da1b4e11390cff3201c19a9a1fe70c5b934f",
              "status": "affected",
              "version": "84c4a9dfbf430861e7588d95ae3ff61535dca351",
              "versionType": "git"
            },
            {
              "lessThan": "136992de9bb91871084ae52d172610541c76e4d2",
              "status": "affected",
              "version": "84c4a9dfbf430861e7588d95ae3ff61535dca351",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a7e22d0c0e81dde129a51ee413644124f4b59954",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "01b0d887f67a388fb2a658ee2bdd74e5ba146818",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "a98124aac0b5adc5de8ae54f11322781cb4d85c3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e27b7bee743d921f037b1da6f071237345bef7c1",
              "versionType": "git"
            },
            {
              "lessThan": "3.1",
              "status": "affected",
              "version": "3.0.79",
              "versionType": "semver"
            },
            {
              "lessThan": "3.3",
              "status": "affected",
              "version": "3.2.46",
              "versionType": "semver"
            },
            {
              "lessThan": "3.5",
              "status": "affected",
              "version": "3.4.46",
              "versionType": "semver"
            },
            {
              "lessThan": "3.10",
              "status": "affected",
              "version": "3.9.3",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/xfrm6_policy.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.10"
            },
            {
              "lessThan": "3.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.148",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
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                },
                {
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.0.79",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.2.46",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.4.46",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.9.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()\n\nOn the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst()\nreleases the device reference with netdev_put() but leaves\nxdst-\u003eu.dst.dev set. dst_destroy() later calls netdev_put(dst-\u003edev)\nagain, so the same net_device reference is released twice, underflowing\nits refcount (ref_tracker WARNING + \"unregister_netdevice: waiting for\n\u003cdev\u003e to become free\").\n\nClear xdst-\u003eu.dst.dev after the netdev_put(), the same way the XFRM\ndevice-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in\nnet/xfrm/xfrm_device.c NULL -\u003edev when releasing the reference on error.\n\n  ref_tracker: reference already released.\n  ref_tracker: allocated in:\n   xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86)\n   ...\n   udpv6_sendmsg (net/ipv6/udp.c:1696)\n   ...\n  ref_tracker: freed in:\n   xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90)\n   ...\n  WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780\n   dst_destroy (net/core/dst.c:115)\n   rcu_core\n   handle_softirqs\n   ..."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is reached on the local IPv6 outbound path (udpv6_sendmsg \u2192 xfrm_lookup \u2192 xfrm6_fill_dst) after configuring XFRM policy/state via netlink or IPV6_XFRM_POLICY; a remote peer cannot drive that configuration or the device state that makes in6_dev_get fail.\nAC:L - An attacker in their own netns can create interfaces, install IPv6 XFRM policy/state, generate matching UDP traffic, and concurrently drop MTU below IPV6_MIN_MTU or unregister the device to clear ip6_ptr, so they control both sides of the window that hits the error path; once entered, the double netdev_put is deterministic.\nPR:L - XFRM configuration requires CAP_NET_ADMIN via netlink_net_capable/sockopt_ns_capable, which is ns_capable() in the netns user_ns, so an unprivileged user obtains it with unshare -Urn rather than real init-namespace root.\nUI:N - No victim action is required; the attacker configures XFRM, manipulates their own netdevs, and sends packets entirely with their own processes.\nS:U - The impact is kernel net_device refcount corruption within the same host kernel authority; this is ordinary local privilege-escalation/DoS territory, not a VM escape or IOMMU/sandbox boundary cross.\nC:H - The leftover dst.dev causes a second netdev_put in dst_destroy, underflowing the net_device refcount and enabling use-after-free of the device object, which per kernel UAF guidance yields a high confidentiality/info-disclosure primitive.\nI:H - A net_device refcount underflow/UAF is heap memory corruption that can be shaped via reuse/spraying into arbitrary write or control-flow hijack, so integrity impact is high.\nA:H - Even without full exploitation, the double put triggers ref_tracker warnings and can oops/panic or hang device unregister (unregister_netdevice waiting for the device to become free), so availability impact is high."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-08T15:13:17.154Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/df6856c2dda9187601d29b5fbd7a81b3b178cedf"
        },
        {
          "url": "https://git.kernel.org/stable/c/43de8a49335e611adb271bbd52e84dfbc11fc185"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff636d7b7cba6dea82ecf580415ea57f2c1a11b6"
        },
        {
          "url": "https://git.kernel.org/stable/c/e078da1b4e11390cff3201c19a9a1fe70c5b934f"
        },
        {
          "url": "https://git.kernel.org/stable/c/136992de9bb91871084ae52d172610541c76e4d2"
        }
      ],
      "title": "xfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64580",
    "datePublished": "2026-08-05T08:09:34.946Z",
    "dateReserved": "2026-07-19T15:36:31.798Z",
    "dateUpdated": "2026-08-08T15:13:17.154Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-G6RX-F8GV-C53J

CVE-2026-64580 (GCVE-0-2026-64580)

Tags

Sightings

Nomenclature