CVE-2024-56654

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

Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating

The usage of rcu_read_(un)lock while inside list_for_each_entry_rcu is

not safe since for the most part entries fetched this way shall be

treated as rcu_dereference:

Note that the value returned by rcu_dereference() is valid

only within the enclosing RCU read-side critical section [1]_.

For example, the following is **not** legal::

rcu_read_lock();

p = rcu_dereference(head.next);

rcu_read_unlock();

x = p->address; /* BUG!!! */

rcu_read_lock();

y = p->data; /* BUG!!! */

rcu_read_unlock();