CVE-2026-63829

The CVE-2026-63829 issue affects the Linux kernel’s GRE/IP tunnel handling: the changelink path for RTM_NEWLINK did not require CAP_NET_ADMIN in the tunnel’s link netns, allowing a caller with CAP_NET_ADMIN in dev_net(dev) but not in t->net to rewrite tunnels. The fix adds rtnl_dev_link_net_ca...