CVE-2026-89477 sctp: fix NULL deref on untransmitted RECONF completion

In the Linux kernel, the following vulnerability has been resolved: sctp: fix NULL deref on untransmitted RECONF completion sctpprocessstrresetoutreq, sctpprocessstrresetaddstrmout and sctpprocessstrresetresp complete a pending stream reconfiguration request by stopping the reconf timer on the...