From: yunshui <jiangyunshui@xxxxxxxxxx> [ Upstream commit d9cbd8343b010016fcaabc361c37720dcafddcbe ] syzbot/KCSAN reported that races happen when multiple CPUs updating dev->stats.tx_error concurrently. Adopt SMP safe DEV_STATS_INC() to update the dev->stats fields. Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: yunshui <jiangyunshui@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Link: https://lore.kernel.org/bpf/20240523033520.4029314-1-jiangyunshui@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/core/filter.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index a3101cdfd47b9..001da7ccb7089 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2266,12 +2266,12 @@ static int __bpf_redirect_neigh_v6(struct sk_buff *skb, struct net_device *dev, err = bpf_out_neigh_v6(net, skb, dev, nh); if (unlikely(net_xmit_eval(err))) - dev->stats.tx_errors++; + DEV_STATS_INC(dev, tx_errors); else ret = NET_XMIT_SUCCESS; goto out_xmit; out_drop: - dev->stats.tx_errors++; + DEV_STATS_INC(dev, tx_errors); kfree_skb(skb); out_xmit: return ret; @@ -2379,12 +2379,12 @@ static int __bpf_redirect_neigh_v4(struct sk_buff *skb, struct net_device *dev, err = bpf_out_neigh_v4(net, skb, dev, nh); if (unlikely(net_xmit_eval(err))) - dev->stats.tx_errors++; + DEV_STATS_INC(dev, tx_errors); else ret = NET_XMIT_SUCCESS; goto out_xmit; out_drop: - dev->stats.tx_errors++; + DEV_STATS_INC(dev, tx_errors); kfree_skb(skb); out_xmit: return ret; -- 2.43.0
