Re: [PATCH net] ptr_ring: fail early if queue occupies more than KMALLOC_MAX_SIZE

[Jason Wang]

On 2018å02æ07æ 16:08, Jason Wang wrote:
> To avoid slab to warn about exceeded size, fail early if queue
> occupies more than KMALLOC_MAX_SIZE.
>
> Reported-by: syzbot+e4d4f9ddd4295539735d@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
>   include/linux/ptr_ring.h | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
> index 1883d61..4b862da 100644
> --- a/include/linux/ptr_ring.h
> +++ b/include/linux/ptr_ring.h
> @@ -466,6 +466,8 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r,
>   
>   static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp)
>   {
> +	if (size > KMALLOC_MAX_SIZE)
> +		return NULL;
>   	return kcalloc(size, sizeof(void *), gfp);
>   }
>   

Fixes: 2e0ab8ca83c12 ("ptr_ring: array based FIFO for pointers")