[PATCH] tracing: dynevent: Add a missing lockdown check on dynevent

["Masami Hiramatsu (Google)" <mhiramat@kernel.org>]

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Since dynamic_events interface on tracefs is compatible with
kprobe_events and uprobe_events, it should also check the lockdown
status and reject if it is set.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/trace_dynevent.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 5d64a18cacac..d06854bd32b3 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -230,6 +230,10 @@ static int dyn_event_open(struct inode *inode, struct file *file)
 {
 	int ret;
 
+	ret = security_locked_down(LOCKDOWN_TRACEFS);
+	if (ret)
+		return ret;
+
 	ret = tracing_check_open_get_tr(NULL);
 	if (ret)
 		return ret;