CVE-2023-54237 net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix potential panic dues to unprotected smcllcsrvaddlink There is a certain chance to trigger the following panic: PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" 0 ffff9456c1cc79a0 machinekexec at...