Re: integer overflows in kernel/relay.c

[Jens Axboe <axboe@kernel.dk>]

On 02/08/2012 11:25 PM, Andrew Morton wrote:
> On Wed, 08 Feb 2012 09:34:16 +0100
> Jens Axboe <axboe@kernel.dk> wrote:
> 
>> On 02/07/2012 03:11 PM, Dan Carpenter wrote:
>>> My static checker is warning about integer overflows in kernel/relay.c
>>>
>>> relay_create_buf()
>>>    170  
>>>    171          buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);
>>>                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>> This can only overflow on 32bit systems.
>>
>> Correct
> 
> This is a relatively common problem.  Converting a kzalloc() call to
> kcalloc() fixes it.  But we do not have a non-zeroing version of
> kcalloc().
> 
> Please, someone complete this patch and send it to me!
> 
> 
> --- a/include/linux/slab.h~a
> +++ a/include/linux/slab.h
> @@ -240,11 +240,16 @@ size_t ksize(const void *);
>   * for general use, and so are not documented here. For a full list of
>   * potential flags, always refer to linux/gfp.h.
>   */
> -static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
> +static inline void *wtf_do_i_call_this(size_t n, size_t size, gfp_t flags)

kzcalloc()? Either that, or long_and_verbose().

-- 
Jens Axboe