Re: [PATCH net] net: fix possible store tearing in neigh_periodic_work()

On Thu, Sep 21, 2023 at 08:46:26AM +0000, Eric Dumazet wrote:

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().

Fixes: 767e97e1e0db ("neigh: RCU conversion of struct neighbour")
Signed-off-by: Eric Dumazet <redacted>

Reviewed-by: Simon Horman <horms@kernel.org>