neigh: disallow un-init_net to change thresh of neigh

thresh and interval are global resources,
only init net can change them.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 86f9b165bbba69482f151010d05ad8fe6243b293..2569ab2cafbe0e557b65a68166d932118a28ffc9 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2049,6 +2049,12 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
                }
        }
 
+       err = -ENOENT;
+       if ((tb[NDTA_THRESH1] || tb[NDTA_THRESH2] ||
+            tb[NDTA_THRESH3] || tb[NDTA_GC_INTERVAL]) &&
+           !net_eq(net, &init_net))
+               goto errout_tbl_lock;
+
        if (tb[NDTA_THRESH1])
                tbl->gc_thresh1 = nla_get_u32(tb[NDTA_THRESH1]);