GHSA-92HV-JCVF-RQG6
Vulnerability from github – Published: 2026-05-28 12:30 – Updated: 2026-05-28 12:30In 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.
{
"affected": [],
"aliases": [
"CVE-2026-46120"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-28T10:16:27Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_gre: Use cached t-\u003enet in ip6erspan_changelink().\n\nAfter commit 5e72ce3e3980 (\"net: ipv6: Use link netns in newlink() of\nrtnl_link_ops\"), ip6erspan_newlink() correctly resolves the per-netns\nip6gre hash via link_net. ip6erspan_changelink() was not converted in\nthat series and still uses dev_net(dev), which diverges from the\ndevice\u0027s creation netns after IFLA_NET_NS_FD migration.\n\nThis re-inserts the tunnel into the wrong per-netns hash. The\noriginal netns keeps a stale entry. When that netns is later\ndestroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a\nslab-use-after-free reported by KASAN, followed by a kernel BUG at\nnet/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify().\n\nReachable from an unprivileged user namespace (unshare --user\n--map-root-user --net).\n\nip6gre_changelink() earlier in the same file already uses the cached\nt-\u003enet; only ip6erspan_changelink() has the wrong shape.",
"id": "GHSA-92hv-jcvf-rqg6",
"modified": "2026-05-28T12:30:29Z",
"published": "2026-05-28T12:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46120"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1d324c2f43f70c965f25c58cc3611c779adbe47e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/311fdd26eb4443d43b909cc67a10f3a5fd1b21b2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cf7fc624329e76c6394653d12353e1d033adea91"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e70cfb40c3a99b232cd42c6a6a10f0d8e039dc82"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eca62bb0569de4d43a4dac06a2092a9d4ca1d702"
}
],
"schema_version": "1.4.0",
"severity": []
}
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.