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

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Date:   Thu, 14 Jun 2018 17:05:36 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     fllinden@...zon.com
Cc:     edumazet@...gle.com, netdev@...r.kernel.org
Subject: Re: [PATCH v3] tcp: verify the checksum of the first data segment
 in a new connection

From: Frank van der Linden <fllinden@...zon.com>
Date: Tue, 12 Jun 2018 23:09:37 +0000

> 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>

Applied and queued up for -stable.

I know you mention the bug causing commit in your commit message,
but you should also still provide a proper Fixes: tag.  I took
care of it for you this time.

Thanks.