CVE-2026-46120
ip6_gre: Use cached t->net in ip6erspan_changelink().
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.
| Vendor | linux |
| Product | linux |
| Ecosystems | |
| Industries | Technology |
| Published | May 28, 2026 |
| Last Updated | Jun 1, 2026 |
Get instant alerts for linux linux
Be the first to know when new high vulnerabilities affecting linux linux are published — delivered to Slack, Telegram or Discord.
CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H