From 7da5492739db745d935a7044288a7307a0fb7f29 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Mon, 16 Dec 2019 16:21:36 +0000
Subject: [PATCH] drm/gma500: fix null dereference of pointer fb before null
 check

Pointer fb is being dereferenced when assigning dev before it
is null checked.  Fix this by only dereferencing dev after the
null check.

Fixes: 6b7ce2c4161a ("drm/gma500: Remove struct psb_fbdev")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191216162136.270114-1-colin.king@canonical.com
---
 drivers/gpu/drm/gma500/accel_2d.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/gma500/accel_2d.c b/drivers/gpu/drm/gma500/accel_2d.c
index b9e5a38632f72..adc0507545bf7 100644
--- a/drivers/gpu/drm/gma500/accel_2d.c
+++ b/drivers/gpu/drm/gma500/accel_2d.c
@@ -228,8 +228,8 @@ static void psbfb_copyarea_accel(struct fb_info *info,
 {
 	struct drm_fb_helper *fb_helper = info->par;
 	struct drm_framebuffer *fb = fb_helper->fb;
-	struct drm_device *dev = fb->dev;
-	struct drm_psb_private *dev_priv = dev->dev_private;
+	struct drm_device *dev;
+	struct drm_psb_private *dev_priv;
 	uint32_t offset;
 	uint32_t stride;
 	uint32_t src_format;
@@ -238,6 +238,8 @@ static void psbfb_copyarea_accel(struct fb_info *info,
 	if (!fb)
 		return;
 
+	dev = fb->dev;
+	dev_priv = dev->dev_private;
 	offset = to_gtt_range(fb->obj[0])->offset;
 	stride = fb->pitches[0];
 
-- 
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