netns: revert "netns: avoid disabling irq for netns id"

This reverts commit bc51dddf98c9 ("netns: avoid disabling irq for
netns id") as it was found to cause problems with systems running
SELinux/audit, see the mailing list thread below:

 * http://marc.info/?t=147694653900002&r=1&w=2

Eventually we should be able to reintroduce this code once we have
rewritten the audit multicast code to queue messages much the same
way we do for unicast messages.  A tracking issue for this can be
found below:

 * https://github.com/linux-audit/audit-kernel/issues/23

Reported-by: Stephen Smalley <sds@tycho.nsa.gov>
Reported-by: Elad Raz <e@eladraz.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 15 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 989434f36f96..f61c0e02a413 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -215,13 +215,14 @@ static void rtnl_net_notifyid(struct net *net, int cmd, int id);
  */
 int peernet2id_alloc(struct net *net, struct net *peer)
 {
+        unsigned long flags;
         bool alloc;
         int id;
 
-        spin_lock_bh(&net->nsid_lock);
+        spin_lock_irqsave(&net->nsid_lock, flags);
         alloc = atomic_read(&peer->count) == 0 ? false : true;
         id = __peernet2id_alloc(net, peer, &alloc);
-        spin_unlock_bh(&net->nsid_lock);
+        spin_unlock_irqrestore(&net->nsid_lock, flags);
         if (alloc && id >= 0)
                 rtnl_net_notifyid(net, RTM_NEWNSID, id);
         return id;
@@ -230,11 +231,12 @@ int peernet2id_alloc(struct net *net, struct net *peer)
 /* This function returns, if assigned, the id of a peer netns. */
 int peernet2id(struct net *net, struct net *peer)
 {
+        unsigned long flags;
         int id;
 
-        spin_lock_bh(&net->nsid_lock);
+        spin_lock_irqsave(&net->nsid_lock, flags);
         id = __peernet2id(net, peer);
-        spin_unlock_bh(&net->nsid_lock);
+        spin_unlock_irqrestore(&net->nsid_lock, flags);
         return id;
 }
 EXPORT_SYMBOL(peernet2id);
@@ -249,17 +251,18 @@ bool peernet_has_id(struct net *net, struct net *peer)
 
 struct net *get_net_ns_by_id(struct net *net, int id)
 {
+        unsigned long flags;
         struct net *peer;
 
         if (id < 0)
                 return NULL;
 
         rcu_read_lock();
-        spin_lock_bh(&net->nsid_lock);
+        spin_lock_irqsave(&net->nsid_lock, flags);
         peer = idr_find(&net->netns_ids, id);
         if (peer)
                 get_net(peer);
-        spin_unlock_bh(&net->nsid_lock);
+        spin_unlock_irqrestore(&net->nsid_lock, flags);
         rcu_read_unlock();
 
         return peer;
@@ -422,17 +425,17 @@ static void cleanup_net(struct work_struct *work)
                 for_each_net(tmp) {
                         int id;
 
-                        spin_lock_bh(&tmp->nsid_lock);
+                        spin_lock_irq(&tmp->nsid_lock);
                         id = __peernet2id(tmp, net);
                         if (id >= 0)
                                 idr_remove(&tmp->netns_ids, id);
-                        spin_unlock_bh(&tmp->nsid_lock);
+                        spin_unlock_irq(&tmp->nsid_lock);
                         if (id >= 0)
                                 rtnl_net_notifyid(tmp, RTM_DELNSID, id);
                 }
-                spin_lock_bh(&net->nsid_lock);
+                spin_lock_irq(&net->nsid_lock);
                 idr_destroy(&net->netns_ids);
-                spin_unlock_bh(&net->nsid_lock);
+                spin_unlock_irq(&net->nsid_lock);
 
         }
         rtnl_unlock();
@@ -561,6 +564,7 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
         struct net *net = sock_net(skb->sk);
         struct nlattr *tb[NETNSA_MAX + 1];
+        unsigned long flags;
         struct net *peer;
         int nsid, err;
 
@@ -581,15 +585,15 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
         if (IS_ERR(peer))
                 return PTR_ERR(peer);
 
-        spin_lock_bh(&net->nsid_lock);
+        spin_lock_irqsave(&net->nsid_lock, flags);
         if (__peernet2id(net, peer) >= 0) {
-                spin_unlock_bh(&net->nsid_lock);
+                spin_unlock_irqrestore(&net->nsid_lock, flags);
                 err = -EEXIST;
                 goto out;
         }
 
         err = alloc_netid(net, peer, nsid);
-        spin_unlock_bh(&net->nsid_lock);
+        spin_unlock_irqrestore(&net->nsid_lock, flags);
         if (err >= 0) {
                 rtnl_net_notifyid(net, RTM_NEWNSID, err);
                 err = 0;
@@ -711,10 +715,11 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
                 .idx = 0,
                 .s_idx = cb->args[0],
         };
+        unsigned long flags;
 
-        spin_lock_bh(&net->nsid_lock);
+        spin_lock_irqsave(&net->nsid_lock, flags);
         idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
-        spin_unlock_bh(&net->nsid_lock);
+        spin_unlock_irqrestore(&net->nsid_lock, flags);
 
         cb->args[0] = net_cb.idx;
         return skb->len;