CVE-2024-43890

In the Linux kernel, the following vulnerability has been resolved:

tracing: Fix overflow in get_free_elt()

"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.

Once it overflows, new elements can still be inserted into the tracing_map even though the maximum number of elements (`max_elts`) has been reached. Continuing to insert elements after the overflow could result in the tracing_map containing "tracing_map->max_size" elements, leaving no empty entries. If any attempt is made to insert an element into a full tracing_map using `__tracing_map_insert()`, it will cause an infinite loop with preemption disabled, leading to a CPU hang problem.

Fix this by preventing any further increments to "tracing_map->next_elt" once it reaches "tracing_map->max_elt".