Re: [PATCH] usb: iowarrior: replace kmalloc with kmalloc_array

[Gustavo A. R. Silva]

On 8/23/18 12:43 PM, Kees Cook wrote:
> On Thu, Aug 23, 2018 at 10:31 AM, Gustavo A. R. Silva
> <gustavo@xxxxxxxxxxxxxx> wrote:
>> A common flaw in the kernel is integer overflow during memory allocation
>> size calculations. In an effort to reduce the frequency of these bugs,
>> kmalloc_array was implemented, which allocates memory for an array,
>> while at the same time detects integer overflow.
>>
>> This patch replaces cases of:
>>
>> kmalloc(a * b, gfp)
>>
>> with:
>>         kmalloc_array(a * b, gfp)
> 
> nit: this should be "kmalloc_array(a, b, gfp)" (This was a typo from
> my treewide commit message... :P)
> 

Oops... OK. V3 is on the way. :P

>> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
>> ---
>>  drivers/usb/misc/iowarrior.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
>> index c2991b8..7a22400 100644
>> --- a/drivers/usb/misc/iowarrior.c
>> +++ b/drivers/usb/misc/iowarrior.c
>> @@ -808,7 +808,7 @@ static int iowarrior_probe(struct usb_interface *interface,
>>                          dev->int_in_endpoint->bInterval);
>>         /* create an internal buffer for interrupt data from the device */
>>         dev->read_queue =
>> -           kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
>> +           kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
>>                     GFP_KERNEL);
> 
> For this patch with the commit log updated:
> 
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> 

Thanks!
--
Gustavo