[PATCH net] net: switchdev: zero-initialize struct switchdev_notifier_fdb_info emitted by drivers towards the bridge

[Ido Schimmel]

On Mon, Aug 09, 2021 at 04:11:52PM +0300, Vladimir Oltean wrote:
> The blamed commit a new field to struct switchdev_notifier_fdb_info, but
> did not make sure that all call paths set it to something valid. For
> example, a switchdev driver may emit a SWITCHDEV_FDB_ADD_TO_BRIDGE
> notifier, and since the 'is_local' flag is not set, it contains junk
> from the stack, so the bridge might interpret those notifications as
> being for local FDB entries when that was not intended.
> 
> To avoid that now and in the future, zero-initialize all
> switchdev_notifier_fdb_info structures created by drivers such that all
> newly added fields to not need to touch drivers again.
> 
> Fixes: 2c4eca3ef716 ("net: bridge: switchdev: include local flag in FDB notifications")
> Reported-by: Ido Schimmel <idosch at idosch.org>
> Signed-off-by: Vladimir Oltean <vladimir.oltean at nxp.com>

Reviewed-by: Ido Schimmel <idosch at nvidia.com>
Tested-by: Ido Schimmel <idosch at nvidia.com>

Thanks