3 files changed, 14 insertions, 7 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 7e4877d9dcb5..725a650bbbb8 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -80,6 +80,7 @@
 #include <linux/delayacct.h>
 #include <linux/seq_file.h>
 #include <linux/pid_namespace.h>
+#include <linux/ptrace.h>
 #include <linux/tracehook.h>
 
 #include <asm/pgtable.h>
@@ -352,6 +353,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
         char state;
         pid_t ppid = 0, pgid = -1, sid = -1;
         int num_threads = 0;
+        int permitted;
         struct mm_struct *mm;
         unsigned long long start_time;
         unsigned long cmin_flt = 0, cmaj_flt = 0;
@@ -364,11 +366,14 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 
         state = *get_task_state(task);
         vsize = eip = esp = 0;
+        permitted = ptrace_may_access(task, PTRACE_MODE_READ);
         mm = get_task_mm(task);
         if (mm) {
                 vsize = task_vsize(mm);
-                eip = KSTK_EIP(task);
-                esp = KSTK_ESP(task);
+                if (permitted) {
+                        eip = KSTK_EIP(task);
+                        esp = KSTK_ESP(task);
+                }
         }
 
         get_task_comm(tcomm, task);
@@ -424,7 +429,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                 unlock_task_sighand(task, &flags);
         }
 
-        if (!whole || num_threads < 2)
+        if (permitted && (!whole || num_threads < 2))
                 wchan = get_wchan(task);
         if (!whole) {
                 min_flt = task->min_flt;
@@ -476,7 +481,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                 rsslim,
                 mm ? mm->start_code : 0,
                 mm ? mm->end_code : 0,
-                mm ? mm->start_stack : 0,
+                (permitted && mm) ? mm->start_stack : 0,
                 esp,
                 eip,
                 /* The signal information here is obsolete.
diff --git a/fs/proc/base.c b/fs/proc/base.c
index aa763ab00777..fb45615943c2 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -322,7 +322,10 @@ static int proc_pid_wchan(struct task_struct *task, char *buffer)
         wchan = get_wchan(task);
 
         if (lookup_symbol_name(wchan, symname) < 0)
-                return sprintf(buffer, "%lu", wchan);
+                if (!ptrace_may_access(task, PTRACE_MODE_READ))
+                        return 0;
+                else
+                        return sprintf(buffer, "%lu", wchan);
         else
                 return sprintf(buffer, "%s", symname);
 }
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 1e15a2b176e8..b080b791d9e3 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -67,8 +67,7 @@ static int proc_get_sb(struct file_system_type *fs_type,
                 sb->s_flags = flags;
                 err = proc_fill_super(sb);
                 if (err) {
-                        up_write(&sb->s_umount);
-                        deactivate_super(sb);
+                        deactivate_locked_super(sb);
                         return err;
                 }