Re: [PATCH net-next v4 00/13] net: page_pool: add netlink-based introspection

[Daniel Golle <daniel@makrotopia.org>]

Hi Eric,

On Wed, Nov 29, 2023 at 10:12:49PM +0100, Eric Dumazet wrote:
> On Wed, Nov 29, 2023 at 9:10 PM Daniel Golle <daniel@makrotopia.org> wrote:
> > Hi Paolo,
> >
> > after the merge of this series to linux-next I'm seeing a new crash
> > during boot.
> > It can absolutely be that this is a bug in the Ethernet driver I'm
> > working on though which only got exposed now. While I'm figuring it
> > out I thought it'd still be good to let you know.
> > [...]
> Please look at the syzbot report
> 
> Proposed patch was :
> 
> diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
> index 1426434a7e1587797da92f3199c0012559b51271..07becd4eceddcd4be9e5bea6479f8ffd16dac851
> 100644
> --- a/net/core/page_pool_user.c
> +++ b/net/core/page_pool_user.c
> @@ -339,7 +339,8 @@ void page_pool_unlist(struct page_pool *pool)
>         mutex_lock(&page_pools_lock);
>         netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_DEL_NTF);
>         xa_erase(&page_pools, pool->user.id);
> -       hlist_del(&pool->user.list);
> +       if (!hlist_unhashed(&pool->user.list))
> +               hlist_del(&pool->user.list);
>         mutex_unlock(&page_pools_lock);
>  }
> 

Confirming that the above patch fixes the issue.

Tested-by: Daniel Golle <daniel@makrotopia.org>