@@ -119,7 +119,7 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct task_struct *task __free(put_task) = NULL;
struct nsproxy *nsp __free(put_nsproxy) = NULL;
struct pid *pid = pidfd_pid(file);
- struct ns_common *ns_common;
+ struct ns_common *ns_common = NULL;
if (arg)
return -EINVAL;
@@ -146,54 +146,73 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
switch (cmd) {
/* Namespaces that hang of nsproxy. */
case PIDFD_GET_CGROUP_NAMESPACE:
- get_cgroup_ns(nsp->cgroup_ns);
- ns_common = to_ns_common(nsp->cgroup_ns);
+ if (IS_ENABLED(CONFIG_CGROUPS)) {
+ get_cgroup_ns(nsp->cgroup_ns);
+ ns_common = to_ns_common(nsp->cgroup_ns);
+ }
break;
case PIDFD_GET_IPC_NAMESPACE:
- get_ipc_ns(nsp->ipc_ns);
- ns_common = to_ns_common(nsp->ipc_ns);
+ if (IS_ENABLED(CONFIG_IPC_NS)) {
+ get_ipc_ns(nsp->ipc_ns);
+ ns_common = to_ns_common(nsp->ipc_ns);
+ }
break;
case PIDFD_GET_MNT_NAMESPACE:
get_mnt_ns(nsp->mnt_ns);
ns_common = to_ns_common(nsp->mnt_ns);
break;
case PIDFD_GET_NET_NAMESPACE:
- ns_common = to_ns_common(nsp->net_ns);
- get_net_ns(ns_common);
+ if (IS_ENABLED(CONFIG_NET_NS)) {
+ ns_common = to_ns_common(nsp->net_ns);
+ get_net_ns(ns_common);
+ }
break;
case PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE:
- get_pid_ns(nsp->pid_ns_for_children);
- ns_common = to_ns_common(nsp->pid_ns_for_children);
+ if (IS_ENABLED(CONFIG_PID_NS)) {
+ get_pid_ns(nsp->pid_ns_for_children);
+ ns_common = to_ns_common(nsp->pid_ns_for_children);
+ }
break;
case PIDFD_GET_TIME_NAMESPACE:
- get_time_ns(nsp->time_ns);
- ns_common = to_ns_common(nsp->time_ns);
- if (!nsp->time_ns)
- return -EINVAL;
+ if (IS_ENABLED(CONFIG_TIME_NS)) {
+ get_time_ns(nsp->time_ns);
+ ns_common = to_ns_common(nsp->time_ns);
+ }
break;
case PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE:
- get_time_ns(nsp->time_ns_for_children);
- ns_common = to_ns_common(nsp->time_ns_for_children);
+ if (IS_ENABLED(CONFIG_TIME_NS)) {
+ get_time_ns(nsp->time_ns_for_children);
+ ns_common = to_ns_common(nsp->time_ns_for_children);
+ }
break;
case PIDFD_GET_UTS_NAMESPACE:
- get_uts_ns(nsp->uts_ns);
- ns_common = to_ns_common(nsp->uts_ns);
+ if (IS_ENABLED(CONFIG_UTS_NS)) {
+ get_uts_ns(nsp->uts_ns);
+ ns_common = to_ns_common(nsp->uts_ns);
+ }
break;
/* Namespaces that don't hang of nsproxy. */
case PIDFD_GET_USER_NAMESPACE:
- rcu_read_lock();
- ns_common = to_ns_common(get_user_ns(task_cred_xxx(task, user_ns)));
- rcu_read_unlock();
+ if (IS_ENABLED(CONFIG_USER_NS)) {
+ rcu_read_lock();
+ ns_common = to_ns_common(get_user_ns(task_cred_xxx(task, user_ns)));
+ rcu_read_unlock();
+ }
break;
case PIDFD_GET_PID_NAMESPACE:
- rcu_read_lock();
- ns_common = to_ns_common(get_pid_ns(task_active_pid_ns(task)));
- rcu_read_unlock();
+ if (IS_ENABLED(CONFIG_PID_NS)) {
+ rcu_read_lock();
+ ns_common = to_ns_common( get_pid_ns(task_active_pid_ns(task)));
+ rcu_read_unlock();
+ }
break;
default:
return -ENOIOCTLCMD;
}
+ if (!ns_common)
+ return -EOPNOTSUPP;
+
/* open_namespace() unconditionally consumes the reference */
return open_namespace(ns_common);
}
The nsproxy structure contains nearly all of the namespaces associated with a task. When a given namespace type is not supported by this kernel the rules whether the corresponding pointer in struct nsproxy is NULL or always init_<ns_type>_ns differ per namespace. Ideally, that wouldn't be the case and for all namespace types we'd always set it to init_<ns_type>_ns when the corresponding namespace type isn't supported. Make sure we handle all namespaces where the pointer in struct nsproxy can be NULL when the namespace type isn't supported. Fixes: 5b08bd408534 ("pidfs: allow retrieval of namespace file descriptors") # mainline only Signed-off-by: Christian Brauner <brauner@kernel.org> --- fs/pidfs.c | 65 +++++++++++++++++++++++++++++++++++------------------- 1 file changed, 42 insertions(+), 23 deletions(-)