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Date:   Wed, 23 Jun 2021 16:22:36 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Paolo Abeni <pabeni@redhat.com>,
        Mat Martineau <mathew.j.martineau@linux.intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 5.10 038/146] mptcp: do not warn on bad input from the
 network
Message-ID: <20210623142235.GA27348@amd>
References: <20210621154911.244649123@linuxfoundation.org>
 <20210621154912.589676201@linuxfoundation.org>
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Hi!

> From: Paolo Abeni <pabeni@redhat.com>
>=20
> [ Upstream commit 61e710227e97172355d5f150d5c78c64175d9fb2 ]
>=20
> 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));
>  }
> =20
> -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=3D%d map_seq=3D%d map_data_len=3D%d",
> -		  ssn, subflow->map_subflow_seq, subflow->map_data_len);
> +	pr_debug("Bad mapping: ssn=3D%d map_seq=3D%d map_data_len=3D%d",
> +		 ssn, subflow->map_subflow_seq, subflow->map_data_len);
>  }
> =20
>  static bool skb_is_fully_mapped(struct sock *ssk, struct sk_buff *skb)

Best regards,
									Pavel
--=20
http://www.livejournal.com/~pavelmachek

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