Re: [dpdk-dev] [PATCH v2] bitmap: fix buffer overrun in bitmap init function

["Dumitrescu, Cristian" <cristian.dumitrescu@intel.com>]

> -----Original Message-----
> From: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> Sent: Wednesday, June 2, 2021 10:49 AM
> To: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
> Cc: dev@dpdk.org; Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>;
> stable@dpdk.org; Andy Moreton <amoreton@xilinx.com>
> Subject: [PATCH v2] bitmap: fix buffer overrun in bitmap init function
> 
> From: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> 
> Bitmap initialization function is allowed to memset()
> caller-provided buffer with number of bytes exceeded
> this buffer size. This happens due to wrong comparison
> sign between buffer size and number of bytes required
> to initialize bitmap.
> 
> Fixes: 602c9ca33a4 ("sched: bitmap is now dynamically allocated")
> Cc: stable@dpdk.org
> 
> Reported-by: Andy Moreton <amoreton@xilinx.com>
> Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> Reviewed-by: Andy Moreton <amoreton@xilinx.com>
> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> ---
>  lib/eal/include/rte_bitmap.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/lib/eal/include/rte_bitmap.h b/lib/eal/include/rte_bitmap.h
> index 9e2b8f2cbf..e4623bb176 100644
> --- a/lib/eal/include/rte_bitmap.h
> +++ b/lib/eal/include/rte_bitmap.h
> @@ -185,9 +185,8 @@ rte_bitmap_init(uint32_t n_bits, uint8_t *mem,
> uint32_t mem_size)
>  	size = __rte_bitmap_get_memory_footprint(n_bits,
>  		&array1_byte_offset, &array1_slabs,
>  		&array2_byte_offset, &array2_slabs);
> -	if (size < mem_size) {
> +	if (size > mem_size)
>  		return NULL;
> -	}
> 
>  	/* Setup bitmap */
>  	memset(mem, 0, size);
> --
> 2.30.2

Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>