diff mbox series

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

Message ID 20210207232120.8885-1-colin.king@canonical.com (mailing list archive)
State New
Delegated to: Jiri Kosina
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,