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Date:   Fri, 20 May 2022 09:34:25 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Matthieu Baerts <matthieu.baerts@tessares.net>
Cc:     davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com,
        pabeni@redhat.com, yoshfuji@linux-ipv6.org, dsahern@kernel.org,
        flyingpeng@tencent.com, imagedong@tencent.com,
        benbjiang@tencent.com
Subject: Re: [PATCH net-next] tcp_ipv6: set the drop_reason in the right
 place
Message-ID: <20220520093425.0489d6d9@kernel.org>
In-Reply-To: <4deccb83-79c4-5276-3183-d6e6ffa3ec53@tessares.net>
References: <20220520021347.2270207-1-kuba@kernel.org>
        <4deccb83-79c4-5276-3183-d6e6ffa3ec53@tessares.net>
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On Fri, 20 May 2022 18:22:22 +0200 Matthieu Baerts wrote:
> On 20/05/2022 04:13, Jakub Kicinski wrote:
> > Looks like the IPv6 version of the patch under Fixes was
> > a copy/paste of the IPv4 but hit the wrong spot.
> > It is tcp_v6_rcv() which uses drop_reason as a boolean, and
> > needs to be protected against reason == 0 before calling free.
> > tcp_v6_do_rcv() has a pretty straightforward flow.  
> 
> Thank you for the patch!
> 
> It looks like this fixes an issue our MPTCP CI detected recently:
> 
> https://github.com/multipath-tcp/mptcp_net-next/issues/277
> 
> 
> Just in case someone else had this issue on their side, here is the call
> trace we had:

Ack, I got the same trace. Let me add the trace to the commit msg and
fast-path merging this fix so more people don't hit the stack trace.