Re: [PATCH] [RFC] net: dsa: mv88e6xxx: Pre-initialize err in mv88e6xxx_port_bridge_join()

From: Vivien Didelot
Date: Mon Apr 25 2016 - 11:03:18 EST


Hi Geert,

Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes:

> drivers/net/dsa/mv88e6xxx.c: In function âmv88e6xxx_port_bridge_joinâ:
> drivers/net/dsa/mv88e6xxx.c:2184: warning: âerrâ may be used uninitialized in this function

Interesting, I don't have those warnings on 207afda1b5036009...

> If netdev_notifier_changeupper_info.upper_dev is ever NULL, the bridge
> parameter will be NULL too, and the function will return an
> uninitialized value.
>
> Pre-initialize err to zero to fix this.
>
> Fixes: 207afda1b5036009 ("net: dsa: mv88e6xxx: share the same default FDB")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> Can this actually happen?

bridge cannot be NULL here. Also ps->ports[port].bridge_dev is assigned
to it before entering the for loop, so _mv88e6xxx_port_based_vlan_map
will be called at least for this port.

Thanks,

Vivien