On Tue, Nov 10, 2020 at 1:16 AM Mao Wenan <[email protected]> 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 <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]> Thanks !
