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-rw-r--r--net/core/net_namespace.c88
1 files changed, 61 insertions, 27 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 2c2eb1b629b1..989434f36f96 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -37,6 +37,8 @@ struct net init_net = {
};
EXPORT_SYMBOL(init_net);
+static bool init_net_initialized;
+
#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
@@ -213,31 +215,29 @@ 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_irqsave(&net->nsid_lock, flags);
+ spin_lock_bh(&net->nsid_lock);
alloc = atomic_read(&peer->count) == 0 ? false : true;
id = __peernet2id_alloc(net, peer, &alloc);
- spin_unlock_irqrestore(&net->nsid_lock, flags);
+ spin_unlock_bh(&net->nsid_lock);
if (alloc && id >= 0)
rtnl_net_notifyid(net, RTM_NEWNSID, id);
return id;
}
-EXPORT_SYMBOL(peernet2id_alloc);
/* 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_irqsave(&net->nsid_lock, flags);
+ spin_lock_bh(&net->nsid_lock);
id = __peernet2id(net, peer);
- spin_unlock_irqrestore(&net->nsid_lock, flags);
+ spin_unlock_bh(&net->nsid_lock);
return id;
}
+EXPORT_SYMBOL(peernet2id);
/* This function returns true is the peer netns has an id assigned into the
* current netns.
@@ -249,18 +249,17 @@ 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_irqsave(&net->nsid_lock, flags);
+ spin_lock_bh(&net->nsid_lock);
peer = idr_find(&net->netns_ids, id);
if (peer)
get_net(peer);
- spin_unlock_irqrestore(&net->nsid_lock, flags);
+ spin_unlock_bh(&net->nsid_lock);
rcu_read_unlock();
return peer;
@@ -310,6 +309,16 @@ out_undo:
#ifdef CONFIG_NET_NS
+static struct ucounts *inc_net_namespaces(struct user_namespace *ns)
+{
+ return inc_ucount(ns, current_euid(), UCOUNT_NET_NAMESPACES);
+}
+
+static void dec_net_namespaces(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_NET_NAMESPACES);
+}
+
static struct kmem_cache *net_cachep;
static struct workqueue_struct *netns_wq;
@@ -351,19 +360,27 @@ void net_drop_ns(void *p)
struct net *copy_net_ns(unsigned long flags,
struct user_namespace *user_ns, struct net *old_net)
{
+ struct ucounts *ucounts;
struct net *net;
int rv;
if (!(flags & CLONE_NEWNET))
return get_net(old_net);
+ ucounts = inc_net_namespaces(user_ns);
+ if (!ucounts)
+ return ERR_PTR(-ENOSPC);
+
net = net_alloc();
- if (!net)
+ if (!net) {
+ dec_net_namespaces(ucounts);
return ERR_PTR(-ENOMEM);
+ }
get_user_ns(user_ns);
mutex_lock(&net_mutex);
+ net->ucounts = ucounts;
rv = setup_net(net, user_ns);
if (rv == 0) {
rtnl_lock();
@@ -372,6 +389,7 @@ struct net *copy_net_ns(unsigned long flags,
}
mutex_unlock(&net_mutex);
if (rv < 0) {
+ dec_net_namespaces(ucounts);
put_user_ns(user_ns);
net_drop_ns(net);
return ERR_PTR(rv);
@@ -404,17 +422,17 @@ static void cleanup_net(struct work_struct *work)
for_each_net(tmp) {
int id;
- spin_lock_irq(&tmp->nsid_lock);
+ spin_lock_bh(&tmp->nsid_lock);
id = __peernet2id(tmp, net);
if (id >= 0)
idr_remove(&tmp->netns_ids, id);
- spin_unlock_irq(&tmp->nsid_lock);
+ spin_unlock_bh(&tmp->nsid_lock);
if (id >= 0)
rtnl_net_notifyid(tmp, RTM_DELNSID, id);
}
- spin_lock_irq(&net->nsid_lock);
+ spin_lock_bh(&net->nsid_lock);
idr_destroy(&net->netns_ids);
- spin_unlock_irq(&net->nsid_lock);
+ spin_unlock_bh(&net->nsid_lock);
}
rtnl_unlock();
@@ -444,6 +462,7 @@ static void cleanup_net(struct work_struct *work)
/* Finally it is safe to free my network namespace structure */
list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
list_del_init(&net->exit_list);
+ dec_net_namespaces(net->ucounts);
put_user_ns(net->user_ns);
net_drop_ns(net);
}
@@ -531,7 +550,7 @@ static struct pernet_operations __net_initdata net_ns_ops = {
.exit = net_ns_net_exit,
};
-static struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
+static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
[NETNSA_NONE] = { .type = NLA_UNSPEC },
[NETNSA_NSID] = { .type = NLA_S32 },
[NETNSA_PID] = { .type = NLA_U32 },
@@ -542,7 +561,6 @@ 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;
@@ -563,15 +581,15 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
if (IS_ERR(peer))
return PTR_ERR(peer);
- spin_lock_irqsave(&net->nsid_lock, flags);
+ spin_lock_bh(&net->nsid_lock);
if (__peernet2id(net, peer) >= 0) {
- spin_unlock_irqrestore(&net->nsid_lock, flags);
+ spin_unlock_bh(&net->nsid_lock);
err = -EEXIST;
goto out;
}
err = alloc_netid(net, peer, nsid);
- spin_unlock_irqrestore(&net->nsid_lock, flags);
+ spin_unlock_bh(&net->nsid_lock);
if (err >= 0) {
rtnl_net_notifyid(net, RTM_NEWNSID, err);
err = 0;
@@ -693,11 +711,10 @@ 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_irqsave(&net->nsid_lock, flags);
+ spin_lock_bh(&net->nsid_lock);
idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
- spin_unlock_irqrestore(&net->nsid_lock, flags);
+ spin_unlock_bh(&net->nsid_lock);
cb->args[0] = net_cb.idx;
return skb->len;
@@ -750,6 +767,8 @@ static int __init net_ns_init(void)
if (setup_net(&init_net, &init_user_ns))
panic("Could not setup the initial network namespace");
+ init_net_initialized = true;
+
rtnl_lock();
list_add_tail_rcu(&init_net.list, &net_namespace_list);
rtnl_unlock();
@@ -811,15 +830,24 @@ static void __unregister_pernet_operations(struct pernet_operations *ops)
static int __register_pernet_operations(struct list_head *list,
struct pernet_operations *ops)
{
+ if (!init_net_initialized) {
+ list_add_tail(&ops->list, list);
+ return 0;
+ }
+
return ops_init(ops, &init_net);
}
static void __unregister_pernet_operations(struct pernet_operations *ops)
{
- LIST_HEAD(net_exit_list);
- list_add(&init_net.exit_list, &net_exit_list);
- ops_exit_list(ops, &net_exit_list);
- ops_free_list(ops, &net_exit_list);
+ if (!init_net_initialized) {
+ list_del(&ops->list);
+ } else {
+ LIST_HEAD(net_exit_list);
+ list_add(&init_net.exit_list, &net_exit_list);
+ ops_exit_list(ops, &net_exit_list);
+ ops_free_list(ops, &net_exit_list);
+ }
}
#endif /* CONFIG_NET_NS */
@@ -996,11 +1024,17 @@ static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
return 0;
}
+static struct user_namespace *netns_owner(struct ns_common *ns)
+{
+ return to_net_ns(ns)->user_ns;
+}
+
const struct proc_ns_operations netns_operations = {
.name = "net",
.type = CLONE_NEWNET,
.get = netns_get,
.put = netns_put,
.install = netns_install,
+ .owner = netns_owner,
};
#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.