Re: [dpdk-dev] [v2] net/i40e: fix integer overflow

[Ye Xiaolong <xiaolong.ye@intel.com>]

On 10/15, Xiao Zhang wrote:
>When config i40e rx queue, the temporary variable to store max packet
>length is not big enough which leads to integer overflow issue. This
>patch is to fix the issue by removing the variable and using the
>expression directly since the variable only used once.
>
>Fixes: 4861cde46116 ("i40e: new poll mode driver")
>Cc: stable@dpdk.org
>
>Signed-off-by: Xiao Zhang <xiao.zhang@intel.com>
>---
>v2
>Correct the fixline and remove temporary variable.
>---
> drivers/net/i40e/i40e_rxtx.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
>index bfe161f..ff6eb4a 100644
>--- a/drivers/net/i40e/i40e_rxtx.c
>+++ b/drivers/net/i40e/i40e_rxtx.c
>@@ -2596,7 +2596,7 @@ i40e_rx_queue_config(struct i40e_rx_queue *rxq)
> 	struct i40e_pf *pf = I40E_VSI_TO_PF(rxq->vsi);
> 	struct i40e_hw *hw = I40E_VSI_TO_HW(rxq->vsi);
> 	struct rte_eth_dev_data *data = pf->dev_data;
>-	uint16_t buf_size, len;
>+	uint16_t buf_size;
> 
> 	buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mp) -
> 		RTE_PKTMBUF_HEADROOM);
>@@ -2619,8 +2619,9 @@ i40e_rx_queue_config(struct i40e_rx_queue *rxq)
> 		break;
> 	}
> 
>-	len = hw->func_caps.rx_buf_chain_len * rxq->rx_buf_len;
>-	rxq->max_pkt_len = RTE_MIN(len, data->dev_conf.rxmode.max_rx_pkt_len);
>+	rxq->max_pkt_len =
>+		RTE_MIN((uint32_t)(hw->func_caps.rx_buf_chain_len *
>+			rxq->rx_buf_len), data->dev_conf.rxmode.max_rx_pkt_len);
> 	if (data->dev_conf.rxmode.offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) {
> 		if (rxq->max_pkt_len <= RTE_ETHER_MAX_LEN ||
> 			rxq->max_pkt_len > I40E_FRAME_SIZE_MAX) {
>-- 
>2.7.4
>

Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>

Applied to dpdk-next-net-intel.