tracing: dynevent: Add a missing lockdown check on dynevent

commit 456c32e3c4316654f95f9d49c12cbecfb77d5660 upstream.

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.

Link: https://lore.kernel.org/all/175824455687.45175.3734166065458520748.stgit@devnote2/
Fixes: 17911ff38aa5 ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index d312a52a10a5b4be5d1c44fc02bca9be9fe35763..8185f57b2e1252e75d2d66301e115e86d477823b 100644 (file)
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -176,6 +176,10 @@ 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;