2019-10-16 03:36:09

by Valentin Vidić

Subject: [PATCH] media: cxusb: fix uninitialized local variable

Make sure ircode does not contain random values if the call to
cxusb_ctrl_msg fails for some reason.

Reported-by: [email protected]
Signed-off-by: Valentin Vidic <[email protected]>
---
drivers/media/usb/dvb-usb/cxusb.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c
index f02fa0a67aa4..afcd88dd96c0 100644
--- a/drivers/media/usb/dvb-usb/cxusb.c
+++ b/drivers/media/usb/dvb-usb/cxusb.c
@@ -519,7 +519,7 @@ static int cxusb_d680_dmb_streaming_ctrl(struct dvb_usb_adapter *adap,

static int cxusb_rc_query(struct dvb_usb_device *d)
{
- u8 ircode[4];
+ u8 ircode[4] = { 0 };

cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4);

@@ -531,7 +531,7 @@ static int cxusb_rc_query(struct dvb_usb_device *d)

static int cxusb_bluebird2_rc_query(struct dvb_usb_device *d)
{
- u8 ircode[4];
+ u8 ircode[4] = { 0 };
struct i2c_msg msg = {
.addr = 0x6b,
.flags = I2C_M_RD,
@@ -550,7 +550,7 @@ static int cxusb_bluebird2_rc_query(struct dvb_usb_device *d)

static int cxusb_d680_dmb_rc_query(struct dvb_usb_device *d)
{
- u8 ircode[2];
+ u8 ircode[2] = { 0 };

if (cxusb_ctrl_msg(d, 0x10, NULL, 0, ircode, 2) < 0)
return 0;
@@ -989,7 +989,7 @@ static int cxusb_dee1601_frontend_attach(struct dvb_usb_adapter *adap)

static int cxusb_dualdig4_frontend_attach(struct dvb_usb_adapter *adap)
{
- u8 ircode[4];
+ u8 ircode[4] = { 0 };
int i;
struct i2c_msg msg = {
.addr = 0x6b,
--
2.20.1

2019-10-16 13:17:01

by Sean Young

Subject: Re: [PATCH] media: cxusb: fix uninitialized local variable

Hi Valentin,

Thank you for your patch.

On Tue, Oct 15, 2019 at 10:03:15PM +0200, Valentin Vidic wrote:
> Make sure ircode does not contain random values if the call to
> cxusb_ctrl_msg fails for some reason.
>
> Reported-by: [email protected]
> Signed-off-by: Valentin Vidic <[email protected]>
> ---
> drivers/media/usb/dvb-usb/cxusb.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c
> index f02fa0a67aa4..afcd88dd96c0 100644
> --- a/drivers/media/usb/dvb-usb/cxusb.c
> +++ b/drivers/media/usb/dvb-usb/cxusb.c
> @@ -519,7 +519,7 @@ static int cxusb_d680_dmb_streaming_ctrl(struct dvb_usb_adapter *adap,
>
> static int cxusb_rc_query(struct dvb_usb_device *d)
> {
> - u8 ircode[4];
> + u8 ircode[4] = { 0 };
>
> cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4);

The correct to do here is check the return value of cxusb_ctrl_msg() and
to not proceed if it failed, rather than assume the value of 0.

Also note that:

https://patchwork.linuxtv.org/patch/59448/

Is already being merged.

Thanks
Sean

>
> @@ -531,7 +531,7 @@ static int cxusb_rc_query(struct dvb_usb_device *d)
>
> static int cxusb_bluebird2_rc_query(struct dvb_usb_device *d)
> {
> - u8 ircode[4];
> + u8 ircode[4] = { 0 };
> struct i2c_msg msg = {
> .addr = 0x6b,
> .flags = I2C_M_RD,
> @@ -550,7 +550,7 @@ static int cxusb_bluebird2_rc_query(struct dvb_usb_device *d)
>
> static int cxusb_d680_dmb_rc_query(struct dvb_usb_device *d)
> {
> - u8 ircode[2];
> + u8 ircode[2] = { 0 };
>
> if (cxusb_ctrl_msg(d, 0x10, NULL, 0, ircode, 2) < 0)
> return 0;
> @@ -989,7 +989,7 @@ static int cxusb_dee1601_frontend_attach(struct dvb_usb_adapter *adap)
>
> static int cxusb_dualdig4_frontend_attach(struct dvb_usb_adapter *adap)
> {
> - u8 ircode[4];
> + u8 ircode[4] = { 0 };
> int i;
> struct i2c_msg msg = {
> .addr = 0x6b,
> --
> 2.20.1