CVE-2026-74609 tipc: read le->link under the node lock in tipc_node_link_down()

In the Linux kernel, the following vulnerability has been resolved: tipc: read le-link under the node lock in tipcnodelinkdown tipcnodelinkdown caches the link pointer before taking n-lock: struct tipclink l = le-link; / unlocked / if !l return; tipcnodewritelockn; if !tipclinkisestablishingl /...