Re: [PATCH net v2] net: netrom: fix lock order inversion in nr_add_node, nr_del_node and nr_dec_obs

Mashiro Chen <[email protected]> Fri, 10 Apr 2026 13:04:00 +0800
Newsgroups org.kernel.vger.linux-hams,org.kernel.vger.linux-kernel,org.kernel.vger.netdev
Message-ID <[email protected]>
On Mon, 6 Apr 2026 Jakub Kicinski wrote:
 > Can we please merge nr_node_list_lock and nr_neigh_list_lock
 > into one instead?

This makes more sense, thanks for the suggestion.
I'll rework the patch to merge the two locks into one and
repost next week.

On 4/10/26 10:54, Jakub Kicinski wrote:
> On Mon,  6 Apr 2026 19:49:04 +0800 Mashiro Chen wrote:
>> nr_del_node() and nr_dec_obs() acquire nr_node_list_lock first, then
>> call nr_remove_neigh() which internally acquires nr_neigh_list_lock.
>> nr_add_node() acquires node_lock first, then calls nr_remove_neigh()
>> which acquires nr_neigh_list_lock.
> Can we please merge nr_node_list_lock and nr_neigh_list_lock
> into one instead?
>
> Lets try to simplify this code as much as possible.
> It's a maintenance nightmare and has fewer users than syzbot reports
> (i'm not joking).