CVE-2024-56640 is a high-severity use-after-free vulnerability in the Linux kernel's net/smc subsystem. The flaw arises from premature decrement of reference counts (refcnt) on LGR/link objects, leading to unsafe resource access. This occurs due to repeated release of LGR/link refcnt without proper locking, specifically in the server listening path where smc_conn_free() is called multiple times without sock lock protection. The issue has been addressed by adding sock lock protection in the smc_listen_work() path to prevent concurrent connection operations from causing refcount underflow.