Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 869e58f8 authored by Denis V. Lunev's avatar Denis V. Lunev Committed by David S. Miller
Browse files

[NETNS]: Double free in netlink_release. 



Netlink protocol table is global for all namespaces. Some netlink
protocols have been virtualized, i.e. they have per/namespace netlink
socket. This difference can easily lead to double free if more than 1
namespace is started. Count the number of kernel netlink sockets to
track that this table is not used any more.

Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Tested-by: default avatarAlexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7d460db9

net/netlink/af_netlink.c

+7 −3
Original line number Diff line number Diff line
@@ -498,9 +498,12 @@ static int netlink_release(struct socket *sock) 


	netlink_table_grab();

	if (netlink_is_kernel(sk)) {

		BUG_ON(nl_table[sk->sk_protocol].registered == 0);

		if (--nl_table[sk->sk_protocol].registered == 0) {

			kfree(nl_table[sk->sk_protocol].listeners);

			nl_table[sk->sk_protocol].module = NULL;

			nl_table[sk->sk_protocol].registered = 0;

		}

	} else if (nlk->subscriptions)

		netlink_update_listeners(sk);

	netlink_table_ungrab();
@@ -1389,6 +1392,7 @@ netlink_kernel_create(struct net *net, int unit, unsigned int groups, 
		nl_table[unit].registered = 1;

	} else {

		kfree(listeners);

		nl_table[unit].registered++;

	}

	netlink_table_ungrab();