Red Hat: CVE-2023-52522: kernel: net: fix possible store tearing in neigh_periodic_work() (Multiple Advisories)

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

net: fix possible store tearing in neigh_periodic_work()

While looking at a related syzbot report involving neigh_periodic_work(),
I found that I forgot to add an annotation when deleting an
RCU protected item from a list.

Readers use rcu_deference(*np), we need to use either
rcu_assign_pointer() or WRITE_ONCE() on writer side
to prevent store tearing.

I use rcu_assign_pointer() to have lockdep support,
this was the choice made in neigh_flush_dev().