Re: [PATCH net v5] net: Update window_clamp if SOCK_RCVBUF is set

[Jakub Kicinski]

On Tue, 10 Nov 2020 08:32:52 +0100 Eric Dumazet wrote:
> On Tue, Nov 10, 2020 at 1:16 AM Mao Wenan <wenan.mao@xxxxxxxxxxxxxxxxx> wrote:
> > When net.ipv4.tcp_syncookies=1 and syn flood is happened,
> > cookie_v4_check or cookie_v6_check tries to redo what
> > tcp_v4_send_synack or tcp_v6_send_synack did,
> > rsk_window_clamp will be changed if SOCK_RCVBUF is set,
> > which will make rcv_wscale is different, the client
> > still operates with initial window scale and can overshot
> > granted window, the client use the initial scale but local
> > server use new scale to advertise window value, and session
> > work abnormally.
> >
> > Fixes: e88c64f0a425 ("tcp: allow effective reduction of TCP's rcv-buffer via setsockopt")
> > Signed-off-by: Mao Wenan <wenan.mao@xxxxxxxxxxxxxxxxx>  
> 
> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>

Applied, thanks!