From: Alexey Kodanev <alexey.koda...@oracle.com>
Date: Tue, 7 Aug 2018 20:03:57 +0300
> The shift of 'cwnd' with '(now - hc->tx_lsndtime) / hc->tx_rto' value
> can lead to undefined behavior [1].
>
> In order to fix this use a gradual shift of the window with a 'while'
> loop, similar to what tcp_cwnd_restart() is doing.
>
> When comparing delta and RTO there is a minor difference between TCP
> and DCCP, the last one also invokes dccp_cwnd_restart() and reduces
> 'cwnd' if delta equals RTO. That case is preserved in this change.
...
> Fixes: 113ced1f52e5 ("dccp ccid-2: Perform congestion-window validation")
> Signed-off-by: Alexey Kodanev <alexey.koda...@oracle.com>
> ---
>
> v2: instead of checking the value with min(), use gradual shifting,
> similar to tcp_cwnd_restart().
Applied and queued up for -stable, thanks.
