hold task_lock around checks in keyctl

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 0291b3f9397c..f1b59ae39d7e 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1486,6 +1486,7 @@ long keyctl_session_to_parent(void)
         oldwork = NULL;
         parent = me->real_parent;
 
+        task_lock(parent);
         /* the parent mustn't be init and mustn't be a kernel thread */
         if (parent->pid <= 1 || !parent->mm)
                 goto unlock;
@@ -1529,6 +1530,7 @@ long keyctl_session_to_parent(void)
         if (!ret)
                 newwork = NULL;
 unlock:
+        task_unlock(parent);
         write_unlock_irq(&tasklist_lock);
         rcu_read_unlock();
         if (oldwork)