netdev - Re: [PATCH v4 net 2/2] net: bridge: switchdev: Ensure deferred event delivery on unoffload

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: <20240214164753.6ij6ksdgz5ailemv@skbuf>
Date: Wed, 14 Feb 2024 18:47:53 +0200
From: Vladimir Oltean <olteanv@...il.com>
To: Tobias Waldekranz <tobias@...dekranz.com>
Cc: davem@...emloft.net, kuba@...nel.org, atenart@...nel.org,
	roopa@...dia.com, razor@...ckwall.org, bridge@...ts.linux.dev,
	netdev@...r.kernel.org, jiri@...nulli.us, ivecera@...hat.com
Subject: Re: [PATCH v4 net 2/2] net: bridge: switchdev: Ensure deferred event
 delivery on unoffload

On Mon, Feb 12, 2024 at 08:18:44PM +0100, Tobias Waldekranz wrote:
> When unoffloading a device, it is important to ensure that all
> relevant deferred events are delivered to it before it disassociates
> itself from the bridge.
> 
> Before this change, this was true for the normal case when a device
> maps 1:1 to a net_bridge_port, i.e.
> 
>    br0
>    /
> swp0
> 
> When swp0 leaves br0, the call to switchdev_deferred_process() in
> del_nbp() makes sure to process any outstanding events while the
> device is still associated with the bridge.
> 
> In the case when the association is indirect though, i.e. when the
> device is attached to the bridge via an intermediate device, like a
> LAG...
> 
>     br0
>     /
>   lag0
>   /
> swp0
> 
> ...then detaching swp0 from lag0 does not cause any net_bridge_port to
> be deleted, so there was no guarantee that all events had been
> processed before the device disassociated itself from the bridge.
> 
> Fix this by always synchronously processing all deferred events before
> signaling completion of unoffloading back to the driver.
> 
> Fixes: 4e51bf44a03a ("net: bridge: move the switchdev object replay helpers to "push" mode")
> Signed-off-by: Tobias Waldekranz <tobias@...dekranz.com>
> ---

Reviewed-by: Vladimir Oltean <olteanv@...il.com>