ptrace: ptrace_attach: fix the usage of ->cred_exec_mutex

ptrace_attach() needs task->cred_exec_mutex, not current->cred_exec_mutex.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index dfcd83ceee3b..0692ab5a0d67 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -188,7 +188,7 @@ int ptrace_attach(struct task_struct *task)
         /* Protect exec's credential calculations against our interference;
          * SUID, SGID and LSM creds get determined differently under ptrace.
          */
-        retval = mutex_lock_interruptible(&current->cred_exec_mutex);
+        retval = mutex_lock_interruptible(&task->cred_exec_mutex);
         if (retval  < 0)
                 goto out;
 
@@ -232,7 +232,7 @@ repeat:
 bad:
         write_unlock_irqrestore(&tasklist_lock, flags);
         task_unlock(task);
-        mutex_unlock(&current->cred_exec_mutex);
+        mutex_unlock(&task->cred_exec_mutex);
 out:
         return retval;
 }