[PATCH net-next] fou: remove warn in gue_gro_receive on unsupported protocol

[PATCH net-next] fou: remove warn in gue_gro_receive on unsupported protocol

[Willem de Bruijn]

From: Willem de Bruijn <willemb@google.com>

Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
not known or does not have a GRO handler.

Such a packet is easily constructed. Syzbot generates them and sets
off this warning.

Remove the warning as it is expected and not actionable.

The warning was previously reduced from WARN_ON to WARN_ON_ONCE in
commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad
proto callbacks").

Signed-off-by: Willem de Bruijn <willemb@google.com>
---
 net/ipv4/fou_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/fou_core.c b/net/ipv4/fou_core.c
index a8494f796dca..0abbc413e0fe 100644
--- a/net/ipv4/fou_core.c
+++ b/net/ipv4/fou_core.c
@@ -433,7 +433,7 @@ static struct sk_buff *gue_gro_receive(struct sock *sk,
 
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
-	if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
+	if (!ops || !ops->callbacks.gro_receive)
 		goto out;
 
 	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
-- 
2.45.2.627.g7a2c4fd464-goog

Re: [PATCH net-next] fou: remove warn in gue_gro_receive on unsupported protocol

[Eric Dumazet]

On Fri, Jun 14, 2024 at 2:25 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> From: Willem de Bruijn <willemb@google.com>
>
> Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
> not known or does not have a GRO handler.
>
> Such a packet is easily constructed. Syzbot generates them and sets
> off this warning.
>
> Remove the warning as it is expected and not actionable.
>
> The warning was previously reduced from WARN_ON to WARN_ON_ONCE in
> commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad
> proto callbacks").
>
> Signed-off-by: Willem de Bruijn <willemb@google.com>

Reviewed-by: Eric Dumazet <edumazet@google.com>

Re: [PATCH net-next] fou: remove warn in gue_gro_receive on unsupported protocol

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 14 Jun 2024 08:25:18 -0400 you wrote:
> From: Willem de Bruijn <willemb@google.com>
> 
> Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
> not known or does not have a GRO handler.
> 
> Such a packet is easily constructed. Syzbot generates them and sets
> off this warning.
> 
> [...]

Here is the summary with links:
  - [net-next] fou: remove warn in gue_gro_receive on unsupported protocol
    https://git.kernel.org/netdev/net-next/c/dd89a81d850f

You are awesome, thank you!
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