userns: Make create_new_namespaces take a user_ns parameter
Modify create_new_namespaces to explicitly take a user namespace
parameter, instead of implicitly through the task_struct.
This allows an implementation of unshare(CLONE_NEWUSER) where
the new user namespace is not stored onto the current task_struct
until after all of the namespaces are created.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 4357a0a..2ddd816 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -57,7 +57,8 @@
* leave it to the caller to do proper locking and attach it to task.
*/
static struct nsproxy *create_new_namespaces(unsigned long flags,
- struct task_struct *tsk, struct fs_struct *new_fs)
+ struct task_struct *tsk, struct user_namespace *user_ns,
+ struct fs_struct *new_fs)
{
struct nsproxy *new_nsp;
int err;
@@ -66,31 +67,31 @@
if (!new_nsp)
return ERR_PTR(-ENOMEM);
- new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, task_cred_xxx(tsk, user_ns), new_fs);
+ new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs);
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);
+ new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->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);
+ new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->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, task_cred_xxx(tsk, user_ns), tsk->nsproxy->pid_ns);
+ new_nsp->pid_ns = copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns);
if (IS_ERR(new_nsp->pid_ns)) {
err = PTR_ERR(new_nsp->pid_ns);
goto out_pid;
}
- new_nsp->net_ns = copy_net_ns(flags, task_cred_xxx(tsk, user_ns), tsk->nsproxy->net_ns);
+ new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns);
if (IS_ERR(new_nsp->net_ns)) {
err = PTR_ERR(new_nsp->net_ns);
goto out_net;
@@ -152,7 +153,8 @@
goto out;
}
- new_ns = create_new_namespaces(flags, tsk, tsk->fs);
+ new_ns = create_new_namespaces(flags, tsk,
+ task_cred_xxx(tsk, user_ns), tsk->fs);
if (IS_ERR(new_ns)) {
err = PTR_ERR(new_ns);
goto out;
@@ -186,6 +188,7 @@
int unshare_nsproxy_namespaces(unsigned long unshare_flags,
struct nsproxy **new_nsp, struct fs_struct *new_fs)
{
+ struct user_namespace *user_ns;
int err = 0;
if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
@@ -195,7 +198,8 @@
if (!nsown_capable(CAP_SYS_ADMIN))
return -EPERM;
- *new_nsp = create_new_namespaces(unshare_flags, current,
+ user_ns = current_user_ns();
+ *new_nsp = create_new_namespaces(unshare_flags, current, user_ns,
new_fs ? new_fs : current->fs);
if (IS_ERR(*new_nsp)) {
err = PTR_ERR(*new_nsp);
@@ -252,7 +256,7 @@
if (nstype && (ops->type != nstype))
goto out;
- new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
+ new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
if (IS_ERR(new_nsproxy)) {
err = PTR_ERR(new_nsproxy);
goto out;
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 4a9362f..fdc619e 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -32,7 +32,7 @@
* @old_ns: namespace to clone
* Return NULL on error (failure to kmalloc), new ns otherwise
*/
-static struct uts_namespace *clone_uts_ns(struct task_struct *tsk,
+static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
struct uts_namespace *old_ns)
{
struct uts_namespace *ns;
@@ -43,7 +43,7 @@
down_read(&uts_sem);
memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
- ns->user_ns = get_user_ns(task_cred_xxx(tsk, user_ns));
+ ns->user_ns = get_user_ns(user_ns);
up_read(&uts_sem);
return ns;
}
@@ -55,9 +55,8 @@
* versa.
*/
struct uts_namespace *copy_utsname(unsigned long flags,
- struct task_struct *tsk)
+ struct user_namespace *user_ns, struct uts_namespace *old_ns)
{
- struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
struct uts_namespace *new_ns;
BUG_ON(!old_ns);
@@ -66,7 +65,7 @@
if (!(flags & CLONE_NEWUTS))
return old_ns;
- new_ns = clone_uts_ns(tsk, old_ns);
+ new_ns = clone_uts_ns(user_ns, old_ns);
put_uts_ns(old_ns);
return new_ns;