On 04/04/2018 04:56 PM, Andrew Lunn wrote:
> The Marvell switches under some conditions will pass a frame to the
> host with the port being the CPU port. Such frames are invalid, and
> should be dropped. Not dropping them can result in a crash when
> incrementing the receive statistics for an invalid port.
>
> Reported-by: Chris Healy <cphe...@gmail.com>
> Fixes: 5f6b4e14cada ("net: dsa: User per-cpu 64-bit statistics")
Are you sure this is the commit that introduced the problem?
> Signed-off-by: Andrew Lunn <and...@lunn.ch>
> ---
> net/dsa/dsa_priv.h | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
> index 70de7895e5b8..6c1bf3d9f652 100644
> --- a/net/dsa/dsa_priv.h
> +++ b/net/dsa/dsa_priv.h
> @@ -126,6 +126,7 @@ static inline struct net_device
> *dsa_master_find_slave(struct net_device *dev,
> struct dsa_port *cpu_dp = dev->dsa_ptr;
> struct dsa_switch_tree *dst = cpu_dp->dst;
> struct dsa_switch *ds;
> + struct dsa_port *slave_port;
>
> if (device < 0 || device >= DSA_MAX_SWITCHES)
> return NULL;
> @@ -137,7 +138,12 @@ static inline struct net_device
> *dsa_master_find_slave(struct net_device *dev,
> if (port < 0 || port >= ds->num_ports)
> return NULL;
>
> - return ds->ports[port].slave;
> + slave_port = &ds->ports[port];
> +
> + if (slave_port->type != DSA_PORT_TYPE_USER)
Can we optimize this with an unlikely()?
> + return NULL;
> +
> + return slave_port->slave;
> }
>
> /* port.c */
>
--
Florian
