From 59d399d357a7705568f424c6e861ee8657f7f655 Mon Sep 17 00:00:00 2001
From: Thomas Renninger <trenn@suse.de>
Date: Tue, 8 Nov 2005 05:27:00 -0500
Subject: [PATCH] [ACPI] Fix Null pointer deref in video/lcd/brightness

http://bugzilla.kernel.org/show_bug.cgi?id=5571

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Yu Luming <luming.yu@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>
---
 drivers/acpi/video.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index f051b151580..d10668f1469 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -812,7 +812,7 @@ acpi_video_device_write_brightness(struct file *file,
 
 	ACPI_FUNCTION_TRACE("acpi_video_device_write_brightness");
 
-	if (!dev || count + 1 > sizeof str)
+	if (!dev || !dev->brightness || count + 1 > sizeof str)
 		return_VALUE(-EINVAL);
 
 	if (copy_from_user(str, buffer, count))
-- 
2.20.1