[PATCH AUTOSEL 5.9 038/147] drm/brige/megachips: Add checking if ge_b850v3_lvds_init() is working correctly

Sasha Levin
2020-10-27T00:34:31Z

From: Nadezda Lutovinova <lutovinova@ispras.ru>

[ Upstream commit f688a345f0d7a6df4dd2aeca8e4f3c05e123a0ee ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

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 6200f12a37e69..ab8174831cf40 100644
--- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
+++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c
@@ -302,8 +302,12 @@ 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);
@@ -361,8 +365,12 @@ 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);
--
2.25.1