sys_getsid/sys_getpgid return wrong id for task from another ns

When calling the sys_getsid/sys_getpgid for task, that actually lives in another namespace (sub-namespace) the return value should be not the id as this task sees it, but the id as the caller does.

---

kernel/sys.c | 18 ++++++++++--------

1 files changed, 10 insertions(+), 8 deletions(-)

index c7c4fa4..c827186 100644
@@ -993,16 +995,17 @@ asmlinkage long sys_getpgid(pid_t pid)

	else {
		int retval;
		struct task_struct *p;

+ struct pid_namespace *ns;

- read_lock(&tasklist_lock);
- p = find_task_by_pid_ns(pid,
- current->nsproxy->pid_ns);
+ ns = current->nsproxy->pid_ns;

+ read_lock(&tasklist_lock);

+		p = find_task_by_pid_ns(pid, ns);
		retval = -ESRCH;
		if (p) {
			retval = security_task_getpgid(p);
			if (!retval)
-				retval = task_pgrp_vnr(p);
+				retval = task_pgrp_nr_ns(p, ns);
		}
		read_unlock(&tasklist_lock);
		return retval;
@@ -1026,16 +1029,17 @@ asmlinkage long sys_getsid(pid_t pid)
	else {
		int retval;
		struct task_struct *p;

+ struct pid_namespace *ns;

- read_lock(&tasklist_lock);
- p = find_task_by_pid_ns(pid,
- current->nsproxy->pid_ns);
+ ns = current->nsproxy->pid_ns;

+ read_lock(&tasklist_lock);

+		p = find_task_by_pid_ns(pid, ns);
		retval = -ESRCH;
		if (p) {
			retval = security_task_getsid(p);
			if (!retval)
-				retval = task_session_vnr(p);
+				retval = task_session_nr_ns(p, ns);
		}
		read_unlock(&tasklist_lock);
		return retval;