1 files changed, 48 insertions, 24 deletions

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 9e83b589f754..a4fb7d46971f 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -21,6 +21,8 @@
 #include <linux/utsname.h>
 #include <linux/pid_namespace.h>
 
+static struct kmem_cache *nsproxy_cachep;
+
 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
 static inline void get_nsproxy(struct nsproxy *ns)
@@ -43,9 +45,11 @@ static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
 {
 	struct nsproxy *ns;
 
-	ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
-	if (ns)
+	ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
+	if (ns) {
+		memcpy(ns, orig, sizeof(struct nsproxy));
 		atomic_set(&ns->count, 1);
+	}
 	return ns;
 }
 
@@ -54,33 +58,51 @@ static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig)
  * Return the newly created nsproxy.  Do not attach this to the task,
  * leave it to the caller to do proper locking and attach it to task.
  */
-static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk,
-			struct fs_struct *new_fs)
+static struct nsproxy *create_new_namespaces(unsigned long flags,
+			struct task_struct *tsk, struct fs_struct *new_fs)
 {
 	struct nsproxy *new_nsp;
+	int err;
 
 	new_nsp = clone_nsproxy(tsk->nsproxy);
 	if (!new_nsp)
 		return ERR_PTR(-ENOMEM);
 
 	new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs);
-	if (IS_ERR(new_nsp->mnt_ns))
+	if (IS_ERR(new_nsp->mnt_ns)) {
+		err = PTR_ERR(new_nsp->mnt_ns);
 		goto out_ns;
+	}
 
 	new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
-	if (IS_ERR(new_nsp->uts_ns))
+	if (IS_ERR(new_nsp->uts_ns)) {
+		err = PTR_ERR(new_nsp->uts_ns);
 		goto out_uts;
+	}
 
 	new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
-	if (IS_ERR(new_nsp->ipc_ns))
+	if (IS_ERR(new_nsp->ipc_ns)) {
+		err = PTR_ERR(new_nsp->ipc_ns);
 		goto out_ipc;
+	}
 
 	new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns);
-	if (IS_ERR(new_nsp->pid_ns))
+	if (IS_ERR(new_nsp->pid_ns)) {
+		err = PTR_ERR(new_nsp->pid_ns);
 		goto out_pid;
+	}
+
+	new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns);
+	if (IS_ERR(new_nsp->user_ns)) {
+		err = PTR_ERR(new_nsp->user_ns);
+		goto out_user;
+	}
 
 	return new_nsp;
 
+out_user:
+	if (new_nsp->pid_ns)
+		put_pid_ns(new_nsp->pid_ns);
 out_pid:
 	if (new_nsp->ipc_ns)
 		put_ipc_ns(new_nsp->ipc_ns);
@@ -91,15 +113,15 @@ out_uts:
 	if (new_nsp->mnt_ns)
 		put_mnt_ns(new_nsp->mnt_ns);
 out_ns:
-	kfree(new_nsp);
-	return ERR_PTR(-ENOMEM);
+	kmem_cache_free(nsproxy_cachep, new_nsp);
+	return ERR_PTR(err);
 }
 
 /*
  * called from clone.  This now handles copy for nsproxy and all
  * namespaces therein.
  */
-int copy_namespaces(int flags, struct task_struct *tsk)
+int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 {
 	struct nsproxy *old_ns = tsk->nsproxy;
 	struct nsproxy *new_ns;
@@ -110,7 +132,7 @@ int copy_namespaces(int flags, struct task_struct *tsk)
 
 	get_nsproxy(old_ns);
 
-	if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
+	if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER)))
 		return 0;
 
 	if (!capable(CAP_SYS_ADMIN)) {
@@ -140,7 +162,9 @@ void free_nsproxy(struct nsproxy *ns)
 		put_ipc_ns(ns->ipc_ns);
 	if (ns->pid_ns)
 		put_pid_ns(ns->pid_ns);
-	kfree(ns);
+	if (ns->user_ns)
+		put_user_ns(ns->user_ns);
+	kmem_cache_free(nsproxy_cachep, ns);
 }
 
 /*
@@ -152,19 +176,10 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 {
 	int err = 0;
 
-	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
+	if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
+			       CLONE_NEWUSER)))
 		return 0;
 
-#ifndef CONFIG_IPC_NS
-	if (unshare_flags & CLONE_NEWIPC)
-		return -EINVAL;
-#endif
-
-#ifndef CONFIG_UTS_NS
-	if (unshare_flags & CLONE_NEWUTS)
-		return -EINVAL;
-#endif
-
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
@@ -174,3 +189,12 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 		err = PTR_ERR(*new_nsp);
 	return err;
 }
+
+static int __init nsproxy_cache_init(void)
+{
+	nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
+					   0, SLAB_PANIC, NULL);
+	return 0;
+}
+
+module_init(nsproxy_cache_init);