linux-kernel - Re: [PATCH net] net: dsa: b53: prevent standalone from trying to forward to other ports

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: <8bf0d3c9-5084-40ff-a338-15f4e0f9d8a0@broadcom.com>
Date: Tue, 13 May 2025 14:43:05 +0200
From: Florian Fainelli <florian.fainelli@...adcom.com>
To: Jonas Gorski <jonas.gorski@...il.com>, Andrew Lunn <andrew@...n.ch>,
 Vladimir Oltean <olteanv@...il.com>, "David S. Miller"
 <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
 Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Cc: Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH net] net: dsa: b53: prevent standalone from trying to
 forward to other ports

On 5/8/2025 11:14 AM, Jonas Gorski wrote:
> When bridged ports and standalone ports share a VLAN, e.g. via VLAN
> uppers, or untagged traffic with a vlan unaware bridge, the ASIC will
> still try to forward traffic to known FDB entries on standalone ports.
> But since the port VLAN masks prevent forwarding to bridged ports, this
> traffic will be dropped.
> 
> This e.g. can be observed in the bridge_vlan_unaware ping tests, where
> this breaks pinging with learning on.
> 
> Work around this by enabling the simplified EAP mode on switches
> supporting it for standalone ports, which causes the ASIC to redirect
> traffic of unknown source MAC addresses to the CPU port.
> 
> Since standalone ports do not learn, there are no known source MAC
> addresses, so effectively this redirects all incoming traffic to the CPU
> port.
> 
> Fixes: ff39c2d68679 ("net: dsa: b53: Add bridge support")
> Signed-off-by: Jonas Gorski <jonas.gorski@...il.com>

Reviewed-by: Florian Fainelli <florian.fainelli@...adcom.com>
-- 
Florian