Re: [PATCH 4.9 040/102] net: dsa: Fix duplicate frames flooded by learning

From: Greg Kroah-Hartman
Date: Tue Apr 07 2020 - 01:42:59 EST


On Mon, Apr 06, 2020 at 05:42:16PM -0700, Florian Fainelli wrote:
>
>
> On 4/1/2020 9:17 AM, Greg Kroah-Hartman wrote:
> > From: Florian Fainelli <f.fainelli@xxxxxxxxx>
> >
> > [ Upstream commit 0e62f543bed03a64495bd2651d4fe1aa4bcb7fe5 ]
> >
> > When both the switch and the bridge are learning about new addresses,
> > switch ports attached to the bridge would see duplicate ARP frames
> > because both entities would attempt to send them.
> >
> > Fixes: 5037d532b83d ("net: dsa: add Broadcom tag RX/TX handler")
> > Reported-by: Maxime Bizon <mbizon@xxxxxxxxxx>
> > Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> > Reviewed-by: Vivien Didelot <vivien.didelot@xxxxxxxxx>
> > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > ---
> > net/dsa/tag_brcm.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > --- a/net/dsa/tag_brcm.c
> > +++ b/net/dsa/tag_brcm.c
> > @@ -84,6 +84,8 @@ static struct sk_buff *brcm_tag_xmit(str
> > brcm_tag[2] = BRCM_IG_DSTMAP2_MASK;
> > brcm_tag[3] = (1 << p->port) & BRCM_IG_DSTMAP1_MASK;
> >
> > + skb->offload_fwd_mark = 1;
>
> This is incorrectly placed, the assignment should be in brcm_tag_rcv().
> It looks like only linux-4.9.y is affected. Sorry for not noticing this
> earlier. Do you want me to submit a correcting patch?

Yes please, that would make it easier for me.

thanks,

greg k-h