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!