net: Set rtm_table to RT_TABLE_COMPAT for ipv6 for tables > 255

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

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 964491cf36720fc3fa5601076002e9c90a4e3302..ce15dc4ccbfa0cc14233b1fe7842479726ffed5a 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1274,18 +1274,29 @@ static DEFINE_SPINLOCK(rt6_exception_lock);
 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
                                 struct rt6_exception *rt6_ex)
 {
+       struct fib6_info *from;
        struct net *net;
 
        if (!bucket || !rt6_ex)
                return;
 
        net = dev_net(rt6_ex->rt6i->dst.dev);
+       net->ipv6.rt6_stats->fib_rt_cache--;
+
+       /* purge completely the exception to allow releasing the held resources:
+        * some [sk] cache may keep the dst around for unlimited time
+        */
+       from = rcu_dereference_protected(rt6_ex->rt6i->from,
+                                        lockdep_is_held(&rt6_exception_lock));
+       rcu_assign_pointer(rt6_ex->rt6i->from, NULL);
+       fib6_info_release(from);
+       dst_dev_put(&rt6_ex->rt6i->dst);
+
        hlist_del_rcu(&rt6_ex->hlist);
        dst_release(&rt6_ex->rt6i->dst);
        kfree_rcu(rt6_ex, rcu);
        WARN_ON_ONCE(!bucket->depth);
        bucket->depth--;
-       net->ipv6.rt6_stats->fib_rt_cache--;
 }
 
 /* Remove oldest rt6_ex in bucket and free the memory
@@ -1599,15 +1610,15 @@ static int rt6_remove_exception_rt(struct rt6_info *rt)
 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 {
        struct rt6_exception_bucket *bucket;
-       struct fib6_info *from = rt->from;
        struct in6_addr *src_key = NULL;
        struct rt6_exception *rt6_ex;
-
-       if (!from ||
-           !(rt->rt6i_flags & RTF_CACHE))
-               return;
+       struct fib6_info *from;
 
        rcu_read_lock();
+       from = rcu_dereference(rt->from);
+       if (!from || !(rt->rt6i_flags & RTF_CACHE))
+               goto unlock;
+
        bucket = rcu_dereference(from->rt6i_exception_bucket);
 
 #ifdef CONFIG_IPV6_SUBTREES
@@ -1626,6 +1637,7 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
        if (rt6_ex)
                rt6_ex->stamp = jiffies;
 
+unlock:
        rcu_read_unlock();
 }
 
@@ -2742,20 +2754,24 @@ static int ip6_route_check_nh_onlink(struct net *net,
        u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
        const struct in6_addr *gw_addr = &cfg->fc_gateway;
        u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;
+       struct fib6_info *from;
        struct rt6_info *grt;
        int err;
 
        err = 0;
        grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);
        if (grt) {
+               rcu_read_lock();
+               from = rcu_dereference(grt->from);
                if (!grt->dst.error &&
                    /* ignore match if it is the default route */
-                   grt->from && !ipv6_addr_any(&grt->from->fib6_dst.addr) &&
+                   from && !ipv6_addr_any(&from->fib6_dst.addr) &&
                    (grt->rt6i_flags & flags || dev != grt->dst.dev)) {
                        NL_SET_ERR_MSG(extack,
                                       "Nexthop has invalid gateway or device mismatch");
                        err = -EINVAL;
                }
+               rcu_read_unlock();
 
                ip6_rt_put(grt);
        }
@@ -4649,7 +4665,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
                table = rt->fib6_table->tb6_id;
        else
                table = RT6_TABLE_UNSPEC;
-       rtm->rtm_table = table;
+       rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
        if (nla_put_u32(skb, RTA_TABLE, table))
                goto nla_put_failure;