1 files changed, 14 insertions, 9 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index ae2b92be5fae..16eda9b39f8d 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -47,12 +47,14 @@
 #include <linux/blkdev.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/tracehook.h>
+#include <linux/init_task.h>
 #include <trace/sched.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
+#include "cred-internals.h"
 
 static void exit_mm(struct task_struct * tsk);
 
@@ -165,7 +167,10 @@ void release_task(struct task_struct * p)
         int zap_leader;
 repeat:
         tracehook_prepare_release_task(p);
-        atomic_dec(&p->user->processes);
+        /* don't need to get the RCU readlock here - the process is dead and
+         * can't be modifying its own credentials */
+        atomic_dec(&__task_cred(p)->user->processes);
+
         proc_flush_task(p);
         write_lock_irq(&tasklist_lock);
         tracehook_finish_release_task(p);
@@ -340,12 +345,12 @@ static void reparent_to_kthreadd(void)
         /* cpus_allowed? */
         /* rt_priority? */
         /* signals? */
-        security_task_reparent_to_init(current);
         memcpy(current->signal->rlim, init_task.signal->rlim,
                sizeof(current->signal->rlim));
-        atomic_inc(&(INIT_USER->__count));
+
+        atomic_inc(&init_cred.usage);
+        commit_creds(&init_cred);
         write_unlock_irq(&tasklist_lock);
-        switch_uid(INIT_USER);
 }
 
 void __set_special_pids(struct pid *pid)
@@ -1087,7 +1092,6 @@ NORET_TYPE void do_exit(long code)
         check_stack_usage();
         exit_thread();
         cgroup_exit(tsk, 1);
-        exit_keys(tsk);
 
         if (group_dead && tsk->signal->leader)
                 disassociate_ctty(1);
@@ -1272,12 +1276,12 @@ static int wait_task_zombie(struct task_struct *p, int options,
         unsigned long state;
         int retval, status, traced;
         pid_t pid = task_pid_vnr(p);
+        uid_t uid = __task_cred(p)->uid;
 
         if (!likely(options & WEXITED))
                 return 0;
 
         if (unlikely(options & WNOWAIT)) {
-                uid_t uid = p->uid;
                 int exit_code = p->exit_code;
                 int why, status;
 
@@ -1398,7 +1402,7 @@ static int wait_task_zombie(struct task_struct *p, int options,
         if (!retval && infop)
                 retval = put_user(pid, &infop->si_pid);
         if (!retval && infop)
-                retval = put_user(p->uid, &infop->si_uid);
+                retval = put_user(uid, &infop->si_uid);
         if (!retval)
                 retval = pid;
 
@@ -1463,7 +1467,8 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
         if (!unlikely(options & WNOWAIT))
                 p->exit_code = 0;
 
-        uid = p->uid;
+        /* don't need the RCU readlock here as we're holding a spinlock */
+        uid = __task_cred(p)->uid;
 unlock_sig:
         spin_unlock_irq(&p->sighand->siglock);
         if (!exit_code)
@@ -1537,10 +1542,10 @@ static int wait_task_continued(struct task_struct *p, int options,
         }
         if (!unlikely(options & WNOWAIT))
                 p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
+        uid = __task_cred(p)->uid;
         spin_unlock_irq(&p->sighand->siglock);
 
         pid = task_pid_vnr(p);
-        uid = p->uid;
         get_task_struct(p);
         read_unlock(&tasklist_lock);