diff mbox series

HID: logitech-dj: fix unintentional integer overflow on left shift

Message ID 20210207232120.8885-1-colin.king@canonical.com
State New
Headers show
Series HID: logitech-dj: fix unintentional integer overflow on left shift | expand

Commit Message

Colin King Feb. 7, 2021, 11:21 p.m. UTC
From: Colin Ian King <colin.king@canonical.com>

Shifting the integer value 1 is evaluated using 32-bit rithmetic
and then used in an expression that expects a 64-bit value, so
there is potentially an integer overflow. Fix this by using th
BIT_ULL macro to perform the shift and avoid the overflow.

Addresses-Coverity: ("Uninitentional integer overflow")
Fixes: 534a7b8e10ec ("HID: Add full support for Logitech Unifying receivers")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/hid/hid-logitech-dj.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Dan Carpenter Feb. 8, 2021, 3:06 p.m. UTC | #1
On Sun, Feb 07, 2021 at 11:21:20PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>

> 

> Shifting the integer value 1 is evaluated using 32-bit rithmetic

> and then used in an expression that expects a 64-bit value, so

> there is potentially an integer overflow. Fix this by using th

> BIT_ULL macro to perform the shift and avoid the overflow.

> 

> Addresses-Coverity: ("Uninitentional integer overflow")

> Fixes: 534a7b8e10ec ("HID: Add full support for Logitech Unifying receivers")

> Signed-off-by: Colin Ian King <colin.king@canonical.com>

> ---

>  drivers/hid/hid-logitech-dj.c | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c

> index 45e7e0bdd382..747f41be0603 100644

> --- a/drivers/hid/hid-logitech-dj.c

> +++ b/drivers/hid/hid-logitech-dj.c

> @@ -1035,7 +1035,7 @@ static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,

>  	memset(reportbuffer, 0, sizeof(reportbuffer));

>  

>  	for (i = 0; i < NUMBER_OF_HID_REPORTS; i++) {

                        ^^^^^^^^^^^^^^^^^^^^^
This is 32, so it can't be undefined.

> -		if (djdev->reports_supported & (1 << i)) {

> +		if (djdev->reports_supported & BIT_ULL(i)) {

>  			reportbuffer[0] = i;

>  			if (hid_input_report(djdev->hdev,

>  					     HID_INPUT_REPORT,


regards,
dan carpenter
Colin King Feb. 8, 2021, 3:07 p.m. UTC | #2
On 08/02/2021 15:06, Dan Carpenter wrote:
> On Sun, Feb 07, 2021 at 11:21:20PM +0000, Colin King wrote:

>> From: Colin Ian King <colin.king@canonical.com>

>>

>> Shifting the integer value 1 is evaluated using 32-bit rithmetic

>> and then used in an expression that expects a 64-bit value, so

>> there is potentially an integer overflow. Fix this by using th

>> BIT_ULL macro to perform the shift and avoid the overflow.

>>

>> Addresses-Coverity: ("Uninitentional integer overflow")

>> Fixes: 534a7b8e10ec ("HID: Add full support for Logitech Unifying receivers")

>> Signed-off-by: Colin Ian King <colin.king@canonical.com>

>> ---

>>  drivers/hid/hid-logitech-dj.c | 2 +-

>>  1 file changed, 1 insertion(+), 1 deletion(-)

>>

>> diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c

>> index 45e7e0bdd382..747f41be0603 100644

>> --- a/drivers/hid/hid-logitech-dj.c

>> +++ b/drivers/hid/hid-logitech-dj.c

>> @@ -1035,7 +1035,7 @@ static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,

>>  	memset(reportbuffer, 0, sizeof(reportbuffer));

>>  

>>  	for (i = 0; i < NUMBER_OF_HID_REPORTS; i++) {

>                         ^^^^^^^^^^^^^^^^^^^^^

> This is 32, so it can't be undefined.


Urgh, looks like coverity is being overly pedantic here. :-(

> 

>> -		if (djdev->reports_supported & (1 << i)) {

>> +		if (djdev->reports_supported & BIT_ULL(i)) {

>>  			reportbuffer[0] = i;

>>  			if (hid_input_report(djdev->hdev,

>>  					     HID_INPUT_REPORT,

> 

> regards,

> dan carpenter

>
diff mbox series

Patch

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 45e7e0bdd382..747f41be0603 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -1035,7 +1035,7 @@  static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,
 	memset(reportbuffer, 0, sizeof(reportbuffer));
 
 	for (i = 0; i < NUMBER_OF_HID_REPORTS; i++) {
-		if (djdev->reports_supported & (1 << i)) {
+		if (djdev->reports_supported & BIT_ULL(i)) {
 			reportbuffer[0] = i;
 			if (hid_input_report(djdev->hdev,
 					     HID_INPUT_REPORT,