1 files changed, 68 insertions, 16 deletions

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index bf727149fdec..1f860340690c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -249,19 +249,33 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
 
 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 {
-	struct fib6_table *tb;
+	struct fib6_table *tb, *new_tb;
 
 	if (id == 0)
 		id = RT6_TABLE_MAIN;
+
 	tb = fib6_get_table(net, id);
 	if (tb)
 		return tb;
 
-	tb = fib6_alloc_table(net, id);
-	if (tb)
-		fib6_link_table(net, tb);
+	new_tb = fib6_alloc_table(net, id);
+	if (!new_tb)
+		return NULL;
+
+	spin_lock_bh(&net->ipv6.fib_table_hash_lock);
+
+	tb = fib6_get_table(net, id);
+	if (unlikely(tb)) {
+		spin_unlock_bh(&net->ipv6.fib_table_hash_lock);
+		kfree(new_tb);
+		return tb;
+	}
 
-	return tb;
+	fib6_link_table(net, new_tb);
+
+	spin_unlock_bh(&net->ipv6.fib_table_hash_lock);
+
+	return new_tb;
 }
 EXPORT_SYMBOL_GPL(fib6_new_table);
 
@@ -1034,8 +1048,14 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
 	rt6_flush_exceptions(rt);
 	fib6_drop_pcpu_from(rt, table);
 
-	if (rt->nh && !list_empty(&rt->nh_list))
-		list_del_init(&rt->nh_list);
+	if (rt->nh) {
+		spin_lock(&rt->nh->lock);
+
+		if (!list_empty(&rt->nh_list))
+			list_del_init(&rt->nh_list);
+
+		spin_unlock(&rt->nh->lock);
+	}
 
 	if (refcount_read(&rt->fib6_ref) != 1) {
 		/* This route is used as dummy address holder in some split
@@ -1069,8 +1089,8 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
  */
 
 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
-			    struct nl_info *info,
-			    struct netlink_ext_ack *extack)
+			    struct nl_info *info, struct netlink_ext_ack *extack,
+			    struct list_head *purge_list)
 {
 	struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
 				    lockdep_is_held(&rt->fib6_table->tb6_lock));
@@ -1294,10 +1314,9 @@ add:
 		}
 		nsiblings = iter->fib6_nsiblings;
 		iter->fib6_node = NULL;
-		fib6_purge_rt(iter, fn, info->nl_net);
+		list_add(&iter->purge_link, purge_list);
 		if (rcu_access_pointer(fn->rr_ptr) == iter)
 			fn->rr_ptr = NULL;
-		fib6_info_release(iter);
 
 		if (nsiblings) {
 			/* Replacing an ECMP route, remove all siblings */
@@ -1310,10 +1329,9 @@ add:
 				if (rt6_qualify_for_ecmp(iter)) {
 					*ins = iter->fib6_next;
 					iter->fib6_node = NULL;
-					fib6_purge_rt(iter, fn, info->nl_net);
+					list_add(&iter->purge_link, purge_list);
 					if (rcu_access_pointer(fn->rr_ptr) == iter)
 						fn->rr_ptr = NULL;
-					fib6_info_release(iter);
 					nsiblings--;
 					info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
 				} else {
@@ -1329,6 +1347,28 @@ add:
 	return 0;
 }
 
+static int fib6_add_rt2node_nh(struct fib6_node *fn, struct fib6_info *rt,
+			       struct nl_info *info, struct netlink_ext_ack *extack,
+			       struct list_head *purge_list)
+{
+	int err;
+
+	spin_lock(&rt->nh->lock);
+
+	if (rt->nh->dead) {
+		NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
+		err = -EINVAL;
+	} else {
+		err = fib6_add_rt2node(fn, rt, info, extack, purge_list);
+		if (!err)
+			list_add(&rt->nh_list, &rt->nh->f6i_list);
+	}
+
+	spin_unlock(&rt->nh->lock);
+
+	return err;
+}
+
 static void fib6_start_gc(struct net *net, struct fib6_info *rt)
 {
 	if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
@@ -1383,6 +1423,7 @@ int fib6_add(struct fib6_node *root, struct fib6_info *rt,
 	     struct nl_info *info, struct netlink_ext_ack *extack)
 {
 	struct fib6_table *table = rt->fib6_table;
+	LIST_HEAD(purge_list);
 	struct fib6_node *fn;
 #ifdef CONFIG_IPV6_SUBTREES
 	struct fib6_node *pn = NULL;
@@ -1485,10 +1526,19 @@ int fib6_add(struct fib6_node *root, struct fib6_info *rt,
 	}
 #endif
 
-	err = fib6_add_rt2node(fn, rt, info, extack);
+	if (rt->nh)
+		err = fib6_add_rt2node_nh(fn, rt, info, extack, &purge_list);
+	else
+		err = fib6_add_rt2node(fn, rt, info, extack, &purge_list);
 	if (!err) {
-		if (rt->nh)
-			list_add(&rt->nh_list, &rt->nh->f6i_list);
+		struct fib6_info *iter, *next;
+
+		list_for_each_entry_safe(iter, next, &purge_list, purge_link) {
+			list_del(&iter->purge_link);
+			fib6_purge_rt(iter, fn, info->nl_net);
+			fib6_info_release(iter);
+		}
+
 		__fib6_update_sernum_upto_root(rt, fib6_new_sernum(info->nl_net));
 
 		if (rt->fib6_flags & RTF_EXPIRES)
@@ -2423,6 +2473,8 @@ static int __net_init fib6_net_init(struct net *net)
 	if (!net->ipv6.fib_table_hash)
 		goto out_rt6_stats;
 
+	spin_lock_init(&net->ipv6.fib_table_hash_lock);
+
 	net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
 					  GFP_KERNEL);
 	if (!net->ipv6.fib6_main_tbl)