CVE-2022-49802 ftrace: Fix null pointer dereference in ftrace_add_mod()

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix null pointer dereference in ftraceaddmod The @ftracemod is allocated by kzalloc, so both the members prev,next of @ftracemode-list are NULL, it's not a valid state to call listdel. If kstrdup for @ftracemod-func|modul...