[PATCH] usb: iowarrior: replace kmalloc with kmalloc_array

[PATCH] usb: iowarrior: replace kmalloc with kmalloc_array

[Gustavo A. R. Silva]

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)

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 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);
 	if (!dev->read_queue)
 		goto error;
-- 
2.7.4

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

[Gustavo A. R. Silva]

Hi,

Please, drop this.

I'll align GFP_KERNEL and send v2.

Thanks
--
Gustavo

On 8/23/18 12:31 PM, Gustavo A. R. Silva 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)
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  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);
>  	if (!dev->read_queue)
>  		goto error;
> 

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

[Kees Cook]

On Thu, Aug 23, 2018 at 10:31 AM, Gustavo A. R. Silva
<gustavo@embeddedor.com> 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)

> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  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@chromium.org>

Thanks!

-Kees

-- 
Kees Cook
Pixel Security

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@embeddedor.com> 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@embeddedor.com>
>> ---
>>  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@chromium.org>
> 

Thanks!
--
Gustavo