drm/brige/megachips: Add checking if ge_b850v3_lvds_init() is working correctly

If ge_b850v3_lvds_init() does not allocate memory for ge_b850v3_lvds_ptr,
then a null pointer dereference is accessed.

The patch adds checking of the return value of ge_b850v3_lvds_init().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Nadezda Lutovinova <lutovinova@ispras.ru>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819143756.30626-1-lutovinova@ispras.ru

diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
index 61a24f2..d2808c4 100644 (file)
--- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
+++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
@@ -310,8 +310,12 @@ static int stdp4028_ge_b850v3_fw_probe(struct i2c_client *stdp4028_i2c,
                                       const struct i2c_device_id *id)
 {
        struct device *dev = &stdp4028_i2c->dev;
+       int ret;
+
+       ret = ge_b850v3_lvds_init(dev);
 
-       ge_b850v3_lvds_init(dev);
+       if (ret)
+               return ret;
 
        ge_b850v3_lvds_ptr->stdp4028_i2c = stdp4028_i2c;
        i2c_set_clientdata(stdp4028_i2c, ge_b850v3_lvds_ptr);
@@ -372,8 +376,12 @@ static int stdp2690_ge_b850v3_fw_probe(struct i2c_client *stdp2690_i2c,
                                       const struct i2c_device_id *id)
 {
        struct device *dev = &stdp2690_i2c->dev;
+       int ret;
+
+       ret = ge_b850v3_lvds_init(dev);
 
-       ge_b850v3_lvds_init(dev);
+       if (ret)
+               return ret;
 
        ge_b850v3_lvds_ptr->stdp2690_i2c = stdp2690_i2c;
        i2c_set_clientdata(stdp2690_i2c, ge_b850v3_lvds_ptr);