leds-pca963x: Fix device tree parsing

A malformed device tree could lead into a segmentation fault if the reg
value of a led is bigger than the number of leds.

A valid device tree could have only information about the last led of the
chip. Fix the device tree parsing to handle those cases.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index 35d56a62f92f..82589c0a5689 100644
--- a/drivers/leds/leds-pca963x.c
+++ b/drivers/leds/leds-pca963x.c
@@ -285,13 +285,13 @@ pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
                 u32 reg;
                 int res;
 
+                res = of_property_read_u32(child, "reg", &reg);
+                if ((res != 0) || (reg >= chip->n_leds))
+                        continue;
                 led.name =
                         of_get_property(child, "label", NULL) ? : child->name;
                 led.default_trigger =
                         of_get_property(child, "linux,default-trigger", NULL);
-                res = of_property_read_u32(child, "reg", &reg);
-                if (res != 0)
-                        continue;
                 pca963x_leds[reg] = led;
         }
         pdata = devm_kzalloc(&client->dev,
@@ -300,7 +300,7 @@ pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
                 return ERR_PTR(-ENOMEM);
 
         pdata->leds.leds = pca963x_leds;
-        pdata->leds.num_leds = count;
+        pdata->leds.num_leds = chip->n_leds;
 
         /* default to open-drain unless totem pole (push-pull) is specified */
         if (of_property_read_bool(np, "nxp,totem-pole"))