HighFix available

ip6_gre: Use cached t->net in ip6erspan_changelink().

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: ip6_gre: Use cached t->net in ip6erspan_changelink(). After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape.

Products: Kernel
Affected versions: Not specified
Fixed versions: 5.10.258, 5.15.209, 6.1.175, 6.12.88, 6.18.30, 6.6.140, 7.0.7
CVEs: CVE-2026-46120
Confirmed fixed CVEs: Not specified
Updated in this feed: 3 Nov 2026, 10:32 UTC · Revision 1

Source evidence

ip6_gre: Use cached t->net in ip6erspan_changelink().

core-osv · Original source

Published 28 May 2026, 09:35 UTC

osv:CVE-2026-46120

Kernel

Fixed versions: 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7

Complete source record

{
  "id": "840800feabce954d3269be5a52b078b0d020885cc8ea370f3c67a31de85f2597",
  "url": "https://osv.dev/vulnerability/CVE-2026-46120",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ip6_gre: Use cached t->net in ip6erspan_changelink().",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ip6_gre: Use cached t->net in ip6erspan_changelink(). After commit 5e72ce3e3980 (\"net: ipv6: Use link netns in newlink() of rtnl_link_ops\"), ip6erspan_newlink() correctly resolves the per-netns ip6gre hash via link_net. ip6erspan_changelink() was not converted in that series and still uses dev_net(dev), which diverges from the device's creation netns after IFLA_NET_NS_FD migration. This re-inserts the tunnel into the wrong per-netns hash. The original netns keeps a stale entry. When that netns is later destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a slab-use-after-free reported by KASAN, followed by a kernel BUG at net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify(). Reachable from an unprivileged user namespace (unshare --user --map-root-user --net). ip6gre_changelink() earlier in the same file already uses the cached t->net; only ip6erspan_changelink() has the wrong shape.",
    "evidence": "osv:CVE-2026-46120",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.258",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.209",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.175",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.140",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.88",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.30",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.7",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-46120",
      "aliases": [
        "CVE-2026-46120"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "2d665034f239412927b1e71329f20f001c92da09"
                },
                {
                  "fixed": "7bd0f2b162b426b343a114e1b329f0d8d14fdc6e"
                },
                {
                  "fixed": "01b71ff2857d3598337de11e7840a8e3ff21553c"
                },
                {
                  "fixed": "0fcf6731706f73494245a9c0d64f93bebf95bb51"
                },
                {
                  "fixed": "eca62bb0569de4d43a4dac06a2092a9d4ca1d702"
                },
                {
                  "fixed": "311fdd26eb4443d43b909cc67a10f3a5fd1b21b2"
                },
                {
                  "fixed": "e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82"
                },
                {
                  "fixed": "cf7fc624329e76c6394653d12353e1d033adea91"
                },
                {
                  "fixed": "1d324c2f43f70c965f25c58cc3611c779adbe47e"
                }
              ]
            },
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "4.16.12"
                },
                {
                  "fixed": "4.17"
                }
              ]
            },
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c6d72628352c949629af619b77b042e0fb5245e7"
                }
              ]
            }
          ],
          "versions": [
            "v4.16.18",
            "v4.16.17",
            "v4.16.16",
            "v4.16.15",
            "v4.16.14",
            "v4.16.13",
            "v4.16.12"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46120.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.17.0"
                },
                {
                  "fixed": "5.10.258"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.209"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.175"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.140"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.88"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.30"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.7"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46120.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.964376256Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-784472.html",
        "https://git.kernel.org/stable/c/01b71ff2857d3598337de11e7840a8e3ff21553c",
        "https://git.kernel.org/stable/c/0fcf6731706f73494245a9c0d64f93bebf95bb51",
        "https://git.kernel.org/stable/c/1d324c2f43f70c965f25c58cc3611c779adbe47e",
        "https://git.kernel.org/stable/c/311fdd26eb4443d43b909cc67a10f3a5fd1b21b2",
        "https://git.kernel.org/stable/c/7bd0f2b162b426b343a114e1b329f0d8d14fdc6e",
        "https://git.kernel.org/stable/c/cf7fc624329e76c6394653d12353e1d033adea91",
        "https://git.kernel.org/stable/c/e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82",
        "https://git.kernel.org/stable/c/eca62bb0569de4d43a4dac06a2092a9d4ca1d702",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46120.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-46120",
        "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/2026/46xxx/CVE-2026-46120.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-46120",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 494541,
  "published_at": "2026-05-28T09:35:35.385+00:00"
}