From: Soheil Hassas Yeganeh <soheil.k...@gmail.com>
Date: Fri, 29 Jul 2016 09:34:02 -0400
> From: Soheil Hassas Yeganeh <soh...@google.com>
>
> tcp_select_initial_window() intends to advertise a window
> scaling for the maximum possible window size. To do so,
> it considers the maximum of net.ipv4.tcp_rmem[2] and
> net.core.rmem_max as the only possible upper-bounds.
> However, users with CAP_NET_ADMIN can use SO_RCVBUFFORCE
> to set the socket's receive buffer size to values
> larger than net.ipv4.tcp_rmem[2] and net.core.rmem_max.
> Thus, SO_RCVBUFFORCE is effectively ignored by
> tcp_select_initial_window().
>
> To fix this, consider the maximum of net.ipv4.tcp_rmem[2],
> net.core.rmem_max and socket's initial buffer space.
>
> Fixes: b0573dea1fb3 ("[NET]: Introduce SO_{SND,RCV}BUFFORCE socket options")
> Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
> Suggested-by: Neal Cardwell <ncardw...@google.com>
Applied, thanks.
