2024-05-23 03:35:48

by Yunshui Jiang

Subject: [PATCH] net: filter: use DEV_STAT_INC()

syzbot/KCSAN reported that races happen when multiple cpus
updating dev->stats.tx_error concurrently.

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

Reported-by: syzbot <[email protected]>
Signed-off-by: yunshui <[email protected]>
---
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 2510464692af..9968db21a29d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2274,12 +2274,12 @@ 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;
@@ -2380,12 +2380,12 @@ 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;
--
2.34.1

2024-05-28 10:10:56

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] net: filter: use DEV_STAT_INC()

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Daniel Borkmann <[email protected]>:

On Thu, 23 May 2024 11:35:20 +0800 you wrote:
> syzbot/KCSAN reported that races happen when multiple cpus
> updating dev->stats.tx_error concurrently.
>
> Adopt SMP safe DEV_STATS_INC() to update dev->stats fields.
>
> Reported-by: syzbot <[email protected]>
> Signed-off-by: yunshui <[email protected]>
>
> [...]

Here is the summary with links:
- net: filter: use DEV_STAT_INC()
https://git.kernel.org/bpf/bpf-next/c/d9cbd8343b01

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html