netdev - Re: [PATCH net] mptcp: be careful on subflow creation

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Message-ID: <4f2a74b9-d728-fa76-7b0f-f70c256077ee@tessares.net>
Date:   Tue, 4 Aug 2020 21:25:44 +0200
From:   Matthieu Baerts <matthieu.baerts@...sares.net>
To:     Paolo Abeni <pabeni@...hat.com>, netdev@...r.kernel.org
Cc:     "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, mptcp@...ts.01.org,
        Nicolas Rybowski <nicolas.rybowski@...sares.net>
Subject: Re: [PATCH net] mptcp: be careful on subflow creation

Hi Paolo,

On 04/08/2020 18:31, Paolo Abeni wrote:
> Nicolas reported the following oops:

(...)

> on some unconventional configuration.
> 
> The MPTCP protocol is trying to create a subflow for an
> unaccepted server socket. That is allowed by the RFC, even
> if subflow creation will likely fail.
> Unaccepted sockets have still a NULL sk_socket field,
> avoid the issue by failing earlier.
> 
> Reported-and-tested-by: Nicolas Rybowski <nicolas.rybowski@...sares.net>
> Fixes: 7d14b0d2b9b3 ("mptcp: set correct vfs info for subflows")

Thank you for the patch, the addition in the code looks very good to me!

But are you sure the commit you mention introduces the issue you fix here?

Cheers,
Matt
-- 
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