Re: [PATCH 5.10 038/146] mptcp: do not warn on bad input from the network

From: Pavel Machek
Date: Wed Jun 23 2021 - 10:22:40 EST


Hi!

> From: Paolo Abeni <pabeni@xxxxxxxxxx>
>
> [ Upstream commit 61e710227e97172355d5f150d5c78c64175d9fb2 ]
>
> warn_bad_map() produces a kernel WARN on bad input coming
> from the network. Use pr_debug() to avoid spamming the system
> log.

So... we switched from WARN _ONCE_ to pr_debug, as many times as we
detect the problem.

Should this be pr_debug_once?

Best regards,
Pavel


> +++ b/net/mptcp/subflow.c
> @@ -655,10 +655,10 @@ static u64 expand_seq(u64 old_seq, u16 old_data_len, u64 seq)
> return seq | ((old_seq + old_data_len + 1) & GENMASK_ULL(63, 32));
> }
>
> -static void warn_bad_map(struct mptcp_subflow_context *subflow, u32 ssn)
> +static void dbg_bad_map(struct mptcp_subflow_context *subflow, u32 ssn)
> {
> - WARN_ONCE(1, "Bad mapping: ssn=%d map_seq=%d map_data_len=%d",
> - ssn, subflow->map_subflow_seq, subflow->map_data_len);
> + pr_debug("Bad mapping: ssn=%d map_seq=%d map_data_len=%d",
> + ssn, subflow->map_subflow_seq, subflow->map_data_len);
> }
>
> static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb)

Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek

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