4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> 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@xxxxxxxxxx> Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> Acked-by: Wei Wang <weiwan@xxxxxxxxxx> Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Benjamin Gilbert <benjamin.gilbert@xxxxxxxxxx> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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;
