[PATCH AUTOSEL 5.15 24/47] bpf, net: Use DEV_STAT_INC()

Sasha Levin
2024-08-01T00:34:44Z

From: yunshui <jiangyunshui@kylinos.cn>

[ 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@googlegroups.com>
Signed-off-by: yunshui <jiangyunshui@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240523033520.4029314-1-jiangyunshui@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 a873c8fd51b67..c5bc9fd3e9275 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2255,12 +2255,12 @@ 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;
@@ -2360,12 +2360,12 @@ 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