net: sparx5: Fix get_stat64 crash in tcpdump

This problem was found with Sparx5 when the tcpdump tool requests the
do_get_stats64 (sparx5_get_stats64) statistic.

The portstats pointer was incorrectly incremented when fetching priority
based statistics.

Fixes: af4b11022e2d (net: sparx5: add ethtool configuration and statistics support)
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Link: https://lore.kernel.org/r/20220203102900.528987-1-steen.hegelund@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_ethtool.c b/drivers/net/ethernet/microchip/sparx5/sparx5_ethtool.c
index 59783fc..10b866e 100644 (file)
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_ethtool.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_ethtool.c
@@ -1103,7 +1103,7 @@ void sparx5_get_stats64(struct net_device *ndev,
        stats->tx_carrier_errors = portstats[spx5_stats_tx_csense_cnt];
        stats->tx_window_errors = portstats[spx5_stats_tx_late_coll_cnt];
        stats->rx_dropped = portstats[spx5_stats_ana_ac_port_stat_lsb_cnt];
-       for (idx = 0; idx < 2 * SPX5_PRIOS; ++idx, ++stats)
+       for (idx = 0; idx < 2 * SPX5_PRIOS; ++idx)
                stats->rx_dropped += portstats[spx5_stats_green_p0_rx_port_drop
                                               + idx];
        stats->tx_dropped = portstats[spx5_stats_tx_local_drop];