diff --git a/net/socket.c b/net/socket.c
index 35dd737..0f75746 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1030,6 +1030,13 @@
 
 	lock_sock(sk);
 
+	spin_lock(&filp->f_lock);
+	if (on)
+		filp->f_flags |= FASYNC;
+	else
+		filp->f_flags &= ~FASYNC;
+	spin_unlock(&filp->f_lock);
+
 	prev = &(sock->fasync_list);
 
 	for (fa = *prev; fa != NULL; prev = &fa->fa_next, fa = *prev)