diff mbox series

[PULL,19/26] hw/display/omap_lcdc: Fix potential NULL pointer dereference

Message ID 20201102171005.30690-20-peter.maydell@linaro.org
State Not Applicable
Headers show
Series target-arm queue | expand

Commit Message

Peter Maydell Nov. 2, 2020, 5:09 p.m. UTC 
From: AlexChen <alex.chen@huawei.com>


In omap_lcd_interrupts(), the pointer omap_lcd is dereferinced before
being check if it is valid, which may lead to NULL pointer dereference.
So move the assignment to surface after checking that the omap_lcd is valid
and move surface_bits_per_pixel(surface) to after the surface assignment.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: AlexChen <alex.chen@huawei.com>

Message-id: 5F9CDB8A.9000001@huawei.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

---
 hw/display/omap_lcdc.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

-- 
2.20.1
diff mbox series

Patch

diff --git a/hw/display/omap_lcdc.c b/hw/display/omap_lcdc.c
index fa4a381db64..58e659c94ff 100644
--- a/hw/display/omap_lcdc.c
+++ b/hw/display/omap_lcdc.c
@@ -78,14 +78,18 @@  static void omap_lcd_interrupts(struct omap_lcd_panel_s *s)
 static void omap_update_display(void *opaque)
 {
     struct omap_lcd_panel_s *omap_lcd = (struct omap_lcd_panel_s *) opaque;
-    DisplaySurface *surface = qemu_console_surface(omap_lcd->con);
+    DisplaySurface *surface;
     draw_line_func draw_line;
     int size, height, first, last;
     int width, linesize, step, bpp, frame_offset;
     hwaddr frame_base;
 
-    if (!omap_lcd || omap_lcd->plm == 1 || !omap_lcd->enable ||
-        !surface_bits_per_pixel(surface)) {
+    if (!omap_lcd || omap_lcd->plm == 1 || !omap_lcd->enable) {
+        return;
+    }
+
+    surface = qemu_console_surface(omap_lcd->con);
+    if (!surface_bits_per_pixel(surface)) {
         return;
     }