Commit cb6ec182 authored Jun 21, 2014 by Himangi Saraogi Committed by Tomi Valkeinen Jun 26, 2014

drivers/video/fbdev : dereference without an error test



After a variable is assigned the result of backlight_device_register, an
error test should be performed before a dereference.

A simplified version of the semantic match that finds this problem is
as follows:

// <smpl>
@def0@
expression x;
position p0;
@@

x@p0 = backlight_device_register(...)

@protected@
expression def0.x,E;
position def0.p0;
position p;
statement S;
@@
x@p0
... when != x = E
if (!IS_ERR(x) && ...) {<... x@p ...>} else S

@unprotected@
expression def0.x,E;
identifier fld;
position def0.p0;
position p != protected.p;
@@
x@p0
... when != x = E
* x@p->fld
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

parent a497c3ba

drivers/video/fbdev/omap2/displays-new/panel-sony-acx565akm.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -817,6 +817,10 @@ static int acx565akm_probe(struct spi_device *spi)

		bldev = backlight_device_register("acx565akm", &ddata->spi->dev,
		ddata, &acx565akm_bl_ops, &props);
		if (IS_ERR(bldev)) {
		r = PTR_ERR(bldev);
		goto err_reg_bl;
		}
		ddata->bl_dev = bldev;
		if (ddata->has_cabc) {
		r = sysfs_create_group(&bldev->dev.kobj, &bldev_attr_group);
		@@ -862,6 +866,7 @@ static int acx565akm_probe(struct spi_device *spi)
		sysfs_remove_group(&bldev->dev.kobj, &bldev_attr_group);
		err_sysfs:
		backlight_device_unregister(bldev);
		err_reg_bl:
		err_detect:
		err_gpio:
		omap_dss_put_device(ddata->in);