linux-kernel - Re: [PATCH net-next] net: veth: Disable netpoll support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1764839728.p54aio6507.astroid@yuna.none>
Date: Thu, 04 Dec 2025 10:20:06 +0100
From: Fabian Grünbichler <f.gruenbichler@...xmox.com>
To: "David S. Miller" <davem@...emloft.net>, Eric Dumazet
	<edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Breno Leitao
	<leitao@...ian.org>, Paolo Abeni <pabeni@...hat.com>
Cc: leit@...a.com, open list <linux-kernel@...r.kernel.org>,
	"open list:NETWORKING DRIVERS" <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next] net: veth: Disable netpoll support

On August 5, 2024 11:40 am, Breno Leitao wrote:
> The current implementation of netpoll in veth devices leads to
> suboptimal behavior, as it triggers warnings due to the invocation of
> __netif_rx() within a softirq context. This is not compliant with
> expected practices, as __netif_rx() has the following statement:
> 
> 	lockdep_assert_once(hardirq_count() | softirq_count());
> 
> Given that veth devices typically do not benefit from the
> functionalities provided by netpoll, Disable netpoll for veth
> interfaces.

this patch seems to have broken combining netconsole and bridges with
veth ports:

https://bugzilla.proxmox.com/show_bug.cgi?id=6873

any chance this is solvable?

> 
> Signed-off-by: Breno Leitao <leitao@...ian.org>
> ---
>  drivers/net/veth.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> index 426e68a95067..34499b91a8bd 100644
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -1696,6 +1696,7 @@ static void veth_setup(struct net_device *dev)
>  	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
>  	dev->priv_flags |= IFF_NO_QUEUE;
>  	dev->priv_flags |= IFF_PHONY_HEADROOM;
> +	dev->priv_flags |= IFF_DISABLE_NETPOLL;
>  
>  	dev->netdev_ops = &veth_netdev_ops;
>  	dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
> -- 
> 2.43.0
> 
> 
> 
>