CVE-2026-74587 sctp: fix use-after-free of cached ASCONF chunk

In the Linux kernel, the following vulnerability has been resolved: sctp: fix use-after-free of cached ASCONF chunk addiplastasconf caches the outstanding outbound ASCONF chunk. The normal ASCONF-ACK completion path releases the chunk and clears the pointer. However, sctpasconfqueueteardown...