4.9-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit 02db55718d53f9d426cee504c27fb768e9ed4ffe upstream.
While rcvbuf is properly clamped by tcp_rmem[2], rcvwin is left to a potentially too big value.
It has no serious effect, since : 1) tcp_grow_window() has very strict checks. 2) window_clamp can be mangled by user space to any value anyway.
tcp_init_buffer_space() and companions use tcp_full_space(), we use tcp_win_from_space() to avoid reloading sk->sk_rcvbuf
Signed-off-by: Eric Dumazet edumazet@google.com Acked-by: Soheil Hassas Yeganeh soheil@google.com Acked-by: Wei Wang weiwan@google.com Acked-by: Neal Cardwell ncardwell@google.com Signed-off-by: David S. Miller davem@davemloft.net Cc: Benjamin Gilbert benjamin.gilbert@coreos.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -636,7 +636,7 @@ void tcp_rcv_space_adjust(struct sock *s sk->sk_rcvbuf = rcvbuf;
/* Make the window clamp follow along. */ - tp->window_clamp = rcvwin; + tp->window_clamp = tcp_win_from_space(rcvbuf); } } tp->rcvq_space.space = copied;