From 775516bfa2bd7993620c9039191a0c30b8d8a496 Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Fri, 18 Jan 2008 23:55:19 -0800 Subject: [NETNS]: Namespace stop vs 'ip r l' race. During network namespace stop process kernel side netlink sockets belonging to a namespace should be closed. They should not prevent namespace to stop, so they do not increment namespace usage counter. Though this counter will be put during last sock_put. The raplacement of the correct netns for init_ns solves the problem only partial as socket to be stoped until proper stop is a valid netlink kernel socket and can be looked up by the user processes. This is not a problem until it resides in initial namespace (no processes inside this net), but this is not true for init_net. So, hold the referrence for a socket, remove it from lookup tables and only after that change namespace and perform a last put. Signed-off-by: Denis V. Lunev Tested-by: Alexey Dobriyan Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) (limited to 'net/core') diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 02cf848f71d2..ddbdde82a700 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1368,25 +1368,14 @@ static int rtnetlink_net_init(struct net *net) rtnetlink_rcv, &rtnl_mutex, THIS_MODULE); if (!sk) return -ENOMEM; - - /* Don't hold an extra reference on the namespace */ - put_net(sk->sk_net); net->rtnl = sk; return 0; } static void rtnetlink_net_exit(struct net *net) { - struct sock *sk = net->rtnl; - if (sk) { - /* At the last minute lie and say this is a socket for the - * initial network namespace. So the socket will be safe to - * free. - */ - sk->sk_net = get_net(&init_net); - netlink_kernel_release(net->rtnl); - net->rtnl = NULL; - } + netlink_kernel_release(net->rtnl); + net->rtnl = NULL; } static struct pernet_operations rtnetlink_net_ops = { -- cgit v1.2.3