Patch "ipv6: fix memory leak with multiple tables during netns destruction" has been added to the 4.13-stable tree

This is a note to let you know that I've just added the patch titled

ipv6: fix memory leak with multiple tables during netns destruction

to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ipv6-fix-memory-leak-with-multiple-tables-during-netns-destruction.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Sabrina Dubroca <[email protected]>
Date: Fri, 8 Sep 2017 10:26:19 +0200
Subject: ipv6: fix memory leak with multiple tables during netns destruction

From: Sabrina Dubroca <[email protected]>

[ Upstream commit ba1cc08d9488c94cb8d94f545305688b72a2a300 ]

fib6_net_exit only frees the main and local tables. If another table was created with fib6_alloc_table, we leak it when the netns is destroyed.

Fix this in the same way ip_fib_net_exit cleans up tables, by walking through the whole hashtable of fib6_table's. We can get rid of the special cases for local and main, since they're also part of the hashtable.

Reproducer:
ip netns add x
ip -net x -6 rule add from 6003:1::/64 table 100 ip netns del x

---
 net/ipv6/ip6_fib.c |   25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

@@ -198,6 +198,12 @@ static void rt6_release(struct rt6_info
 	}
 }
 
+static void fib6_free_table(struct fib6_table *table)
+{
+	inetpeer_invalidate_tree(&table->tb6_peers);
+	kfree(table);
+}
+
 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 {
 	unsigned int h;

@@ -1915,15 +1921,22 @@ out_timer:
 
 static void fib6_net_exit(struct net *net)
 {
+	unsigned int i;
+
 	rt6_ifdown(net, NULL);
 	del_timer_sync(&net->ipv6.ip6_fib_timer);
 
-#ifdef CONFIG_IPV6_MULTIPLE_TABLES
-	inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
-	kfree(net->ipv6.fib6_local_tbl);
-#endif
-	inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
-	kfree(net->ipv6.fib6_main_tbl);
+	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+		struct hlist_head *head = &net->ipv6.fib_table_hash[i];
+		struct hlist_node *tmp;
+		struct fib6_table *tb;
+
+		hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
+			hlist_del(&tb->tb6_hlist);
+			fib6_free_table(tb);
+		}
+	}
+
 	kfree(net->ipv6.fib_table_hash);
 	kfree(net->ipv6.rt6_stats);
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.13/ipv6-fix-memory-leak-with-multiple-tables-during-netns-destruction.patch