macsec: use DEV_STATS_INC()

[ Upstream commit 32d0a49d36a2a306c2e47fe5659361e424f0ed3f ]

syzbot/KCSAN reported data-races in macsec whenever dev->stats fields
are updated.

It appears all of these updates can happen from multiple cpus.

Adopt SMP safe DEV_STATS_INC() to update dev->stats fields.

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index e7af0e7a296783acf1a0cddf3c02132941f6f16c..98ce24422424c3e49953873892965dfc6fff2f0f 100644 (file)
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -761,7 +761,7 @@ static bool macsec_post_decrypt(struct sk_buff *skb, struct macsec_secy *secy, u
                u64_stats_update_begin(&rxsc_stats->syncp);
                rxsc_stats->stats.InPktsLate++;
                u64_stats_update_end(&rxsc_stats->syncp);
-               secy->netdev->stats.rx_dropped++;
+               DEV_STATS_INC(secy->netdev, rx_dropped);
                return false;
        }
 
@@ -785,7 +785,7 @@ static bool macsec_post_decrypt(struct sk_buff *skb, struct macsec_secy *secy, u
                        rxsc_stats->stats.InPktsNotValid++;
                        u64_stats_update_end(&rxsc_stats->syncp);
                        this_cpu_inc(rx_sa->stats->InPktsNotValid);
-                       secy->netdev->stats.rx_errors++;
+                       DEV_STATS_INC(secy->netdev, rx_errors);
                        return false;
                }
 
@@ -1071,7 +1071,7 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
                        u64_stats_update_begin(&secy_stats->syncp);
                        secy_stats->stats.InPktsNoTag++;
                        u64_stats_update_end(&secy_stats->syncp);
-                       macsec->secy.netdev->stats.rx_dropped++;
+                       DEV_STATS_INC(macsec->secy.netdev, rx_dropped);
                        continue;
                }
 
@@ -1181,7 +1181,7 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
                u64_stats_update_begin(&secy_stats->syncp);
                secy_stats->stats.InPktsBadTag++;
                u64_stats_update_end(&secy_stats->syncp);
-               secy->netdev->stats.rx_errors++;
+               DEV_STATS_INC(secy->netdev, rx_errors);
                goto drop_nosa;
        }
 
@@ -1198,7 +1198,7 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
                        u64_stats_update_begin(&rxsc_stats->syncp);
                        rxsc_stats->stats.InPktsNotUsingSA++;
                        u64_stats_update_end(&rxsc_stats->syncp);
-                       secy->netdev->stats.rx_errors++;
+                       DEV_STATS_INC(secy->netdev, rx_errors);
                        if (active_rx_sa)
                                this_cpu_inc(active_rx_sa->stats->InPktsNotUsingSA);
                        goto drop_nosa;
@@ -1232,7 +1232,7 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
                        u64_stats_update_begin(&rxsc_stats->syncp);
                        rxsc_stats->stats.InPktsLate++;
                        u64_stats_update_end(&rxsc_stats->syncp);
-                       macsec->secy.netdev->stats.rx_dropped++;
+                       DEV_STATS_INC(macsec->secy.netdev, rx_dropped);
                        goto drop;
                }
        }
@@ -1273,7 +1273,7 @@ deliver:
        if (ret == NET_RX_SUCCESS)
                count_rx(dev, len);
        else
-               macsec->secy.netdev->stats.rx_dropped++;
+               DEV_STATS_INC(macsec->secy.netdev, rx_dropped);
 
        rcu_read_unlock();
 
@@ -1310,7 +1310,7 @@ nosci:
                        u64_stats_update_begin(&secy_stats->syncp);
                        secy_stats->stats.InPktsNoSCI++;
                        u64_stats_update_end(&secy_stats->syncp);
-                       macsec->secy.netdev->stats.rx_errors++;
+                       DEV_STATS_INC(macsec->secy.netdev, rx_errors);
                        continue;
                }
 
@@ -1329,7 +1329,7 @@ nosci:
                        secy_stats->stats.InPktsUnknownSCI++;
                        u64_stats_update_end(&secy_stats->syncp);
                } else {
-                       macsec->secy.netdev->stats.rx_dropped++;
+                       DEV_STATS_INC(macsec->secy.netdev, rx_dropped);
                }
        }
 
@@ -3438,7 +3438,7 @@ static netdev_tx_t macsec_start_xmit(struct sk_buff *skb,
 
        if (!secy->operational) {
                kfree_skb(skb);
-               dev->stats.tx_dropped++;
+               DEV_STATS_INC(dev, tx_dropped);
                return NETDEV_TX_OK;
        }
 
@@ -3446,7 +3446,7 @@ static netdev_tx_t macsec_start_xmit(struct sk_buff *skb,
        skb = macsec_encrypt(skb, dev);
        if (IS_ERR(skb)) {
                if (PTR_ERR(skb) != -EINPROGRESS)
-                       dev->stats.tx_dropped++;
+                       DEV_STATS_INC(dev, tx_dropped);
                return NETDEV_TX_OK;
        }
 
@@ -3680,9 +3680,9 @@ static void macsec_get_stats64(struct net_device *dev,
 
        dev_fetch_sw_netstats(s, dev->tstats);
 
-       s->rx_dropped = dev->stats.rx_dropped;
-       s->tx_dropped = dev->stats.tx_dropped;
-       s->rx_errors = dev->stats.rx_errors;
+       s->rx_dropped = atomic_long_read(&dev->stats.__rx_dropped);
+       s->tx_dropped = atomic_long_read(&dev->stats.__tx_dropped);
+       s->rx_errors = atomic_long_read(&dev->stats.__rx_errors);
 }
 
 static int macsec_get_iflink(const struct net_device *dev)