From 1691563a36be565713d39812eaeb708dcfd24911 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 23 Mar 2018 14:37:36 +0300
Subject: [PATCH 1784/1795] tracing: Fix a potential NULL dereference

We forgot to set the error code on this path so we return ERR_PTR(0)
which is NULL.  It results in a NULL dereference in the caller.

Link: http://lkml.kernel.org/r/20180323113735.GC28518@mwanda

Fixes: 100719dcef44 ("tracing: Add simple expression support to hist triggers")
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit 5e4cf2bf6d1c198a90ccc0df5ffd8e0d4ea36b48)
Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 kernel/trace/trace_events_hist.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 4f027642ceef..a02bc09d765a 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2776,6 +2776,7 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
 		expr->fn = hist_field_plus;
 		break;
 	default:
+		ret = -EINVAL;
 		goto free;
 	}
 
-- 
2.19.0