CVE-2026-68162 sctp: avoid auth_enable sysctl UAF during netns teardown

In the Linux kernel, the following vulnerability has been resolved: sctp: avoid authenable sysctl UAF during netns teardown procsctpdoauth updates the SCTP control socket after changing net.sctp.authenable. The handler gets the per-net SCTP state from ctl-data, so an already opened sysctl file ca...