[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: Denis V. Lunev <den@openvz.org>
Tested-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Denis V. Lunev 2008-01-18 23:53:31 -08:00 committed by David S. Miller
parent 7d460db953
commit 869e58f870

View File

@ -498,9 +498,12 @@ static int netlink_release(struct socket *sock)
netlink_table_grab();
if (netlink_is_kernel(sk)) {
kfree(nl_table[sk->sk_protocol].listeners);
nl_table[sk->sk_protocol].module = NULL;
nl_table[sk->sk_protocol].registered = 0;
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();