netdev - Re: [PATCH v3] tcp: verify the checksum of the first data segment in a new connection

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Date:   Tue, 12 Jun 2018 21:45:35 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     Frank van der Linden <fllinden@...zon.com>, edumazet@...gle.com,
        netdev@...r.kernel.org
Subject: Re: [PATCH v3] tcp: verify the checksum of the first data segment in
 a new connection



On 06/12/2018 04:09 PM, Frank van der Linden wrote:
> commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash
> table") introduced an optimization for the handling of child sockets
> created for a new TCP connection.
> 
> But this optimization passes any data associated with the last ACK of the
> connection handshake up the stack without verifying its checksum, because it
> calls tcp_child_process(), which in turn calls tcp_rcv_state_process()
> directly.  These lower-level processing functions do not do any checksum
> verification.
> 
> Insert a tcp_checksum_complete call in the TCP_NEW_SYN_RECEIVE path to
> fix this.
> 
> Signed-off-by: Frank van der Linden <fllinden@...zon.com>

Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Thanks !