sys_getppid: add missing rcu_dereference
In order to safely dereference current->real_parent inside an
rcu_read_lock, we need an rcu_dereference.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/timer.c b/kernel/timer.c
index dbaa624..9c3c62b 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1368,7 +1368,7 @@
int pid;
rcu_read_lock();
- pid = task_tgid_vnr(current->real_parent);
+ pid = task_tgid_vnr(rcu_dereference(current->real_parent));
rcu_read_unlock();
return pid;