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();

Affected Software

References

• https://git.kernel.org/stable/c/0108132d7d76d884e443d18b4f067cdf2811911b
• https://git.kernel.org/stable/c/581dd2dc168fe0ed2a7a5534a724f0d3751c93ae
• https://git.kernel.org/stable/c/f9ecc90b5d501b3a5a62d0685d5104f934bb0104