Merge tag 'selinux-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git...

[sfrench/cifs-2.6.git] / net / ipv6 / syncookies.c

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 0351e2ffc707f379851ad9c679bd7467fb2fa046..e8cfb9e997bf062d24cf3e4d4e95a447890c7952 100644 (file)
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -136,7 +136,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
        __u32 cookie = ntohl(th->ack_seq) - 1;
        struct sock *ret = sk;
        struct request_sock *req;
-       int mss;
+       int full_space, mss;
        struct dst_entry *dst;
        __u8 rcv_wscale;
        u32 tsoff = 0;
@@ -241,7 +241,13 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
        }
 
        req->rsk_window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
-       tcp_select_initial_window(sk, tcp_full_space(sk), req->mss,
+       /* limit the window selection if the user enforce a smaller rx buffer */
+       full_space = tcp_full_space(sk);
+       if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
+           (req->rsk_window_clamp > full_space || req->rsk_window_clamp == 0))
+               req->rsk_window_clamp = full_space;
+
+       tcp_select_initial_window(sk, full_space, req->mss,
                                  &req->rsk_rcv_wnd, &req->rsk_window_clamp,
                                  ireq->wscale_ok, &rcv_wscale,
                                  dst_metric(dst, RTAX_INITRWND));