In the Linux kernel, the following vulnerability has been resolved: tracing: Hold trace_types_lock when updating modules in persistent instances trace_module_record() walks ftrace_trace_arrays from the module notifier without trace_types_lock. A concurrent rmdir of an instance removes it from the list and frees it under that lock, so a module load or unload can walk into a freed trace_array.
https://git.kernel.org/stable/c/dab2bd4d67ad5eaa95019a9511f8d379401b5021
https://git.kernel.org/stable/c/57408eac99b0d8a005796346d317d31f0ca4e07a
https://git.kernel.org/stable/c/244c442f54601a24c86ad90572bf36fc3df41c5e