[dpdk-dev] [PATCH] net/ice: fix integer overflow when computing max_pkt_len

[Tudor Cornea <tudor.cornea.keysight@gmail.com>]

The len variable, used in the computation of max_pkt_len could overflow,
if used to store the result of the following computation:

ICE_SUPPORT_CHAIN_NUM * rxq->rx_buf_len

Since, we could define the mbuf size to have a large value (i.e 13312),
and ICE_SUPPORT_CHAIN_NUM is defined as 5, the computation mentioned
above could potentially result in a value which might be bigger than
MAX_USHORT.

The result will be that Jumbo Frames will not work properly

Signed-off-by: Tudor Cornea <tudor.cornea@keysight.com>
---
 drivers/net/ice/ice_dcf_ethdev.c | 7 ++++---
 drivers/net/ice/ice_rxtx.c       | 6 +++---
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ice/ice_dcf_ethdev.c b/drivers/net/ice/ice_dcf_ethdev.c
index b937cbb..f73dc80 100644
--- a/drivers/net/ice/ice_dcf_ethdev.c
+++ b/drivers/net/ice/ice_dcf_ethdev.c
@@ -54,13 +54,14 @@ ice_dcf_init_rxq(struct rte_eth_dev *dev, struct ice_rx_queue *rxq)
 	struct ice_dcf_adapter *dcf_ad = dev->data->dev_private;
 	struct rte_eth_dev_data *dev_data = dev->data;
 	struct iavf_hw *hw = &dcf_ad->real_hw.avf;
-	uint16_t buf_size, max_pkt_len, len;
+	uint16_t buf_size, max_pkt_len;
 
 	buf_size = rte_pktmbuf_data_room_size(rxq->mp) - RTE_PKTMBUF_HEADROOM;
 	rxq->rx_hdr_len = 0;
 	rxq->rx_buf_len = RTE_ALIGN(buf_size, (1 << ICE_RLAN_CTX_DBUF_S));
-	len = ICE_SUPPORT_CHAIN_NUM * rxq->rx_buf_len;
-	max_pkt_len = RTE_MIN(len, dev->data->dev_conf.rxmode.max_rx_pkt_len);
+	max_pkt_len = RTE_MIN((uint32_t)
+			      ICE_SUPPORT_CHAIN_NUM * rxq->rx_buf_len,
+			      dev->data->dev_conf.rxmode.max_rx_pkt_len);
 
 	/* Check if the jumbo frame and maximum packet length are set
 	 * correctly.
diff --git a/drivers/net/ice/ice_rxtx.c b/drivers/net/ice/ice_rxtx.c
index fc9bb5a..20352b0 100644
--- a/drivers/net/ice/ice_rxtx.c
+++ b/drivers/net/ice/ice_rxtx.c
@@ -258,7 +258,7 @@ ice_program_hw_rx_queue(struct ice_rx_queue *rxq)
 	struct rte_eth_dev_data *dev_data = rxq->vsi->adapter->pf.dev_data;
 	struct ice_rlan_ctx rx_ctx;
 	enum ice_status err;
-	uint16_t buf_size, len;
+	uint16_t buf_size;
 	struct rte_eth_rxmode *rxmode = &dev_data->dev_conf.rxmode;
 	uint32_t rxdid = ICE_RXDID_COMMS_OVS;
 	uint32_t regval;
@@ -268,8 +268,8 @@ ice_program_hw_rx_queue(struct ice_rx_queue *rxq)
 			      RTE_PKTMBUF_HEADROOM);
 	rxq->rx_hdr_len = 0;
 	rxq->rx_buf_len = RTE_ALIGN(buf_size, (1 << ICE_RLAN_CTX_DBUF_S));
-	len = ICE_SUPPORT_CHAIN_NUM * rxq->rx_buf_len;
-	rxq->max_pkt_len = RTE_MIN(len,
+	rxq->max_pkt_len = RTE_MIN((uint32_t)
+				   ICE_SUPPORT_CHAIN_NUM * rxq->rx_buf_len,
 				   dev_data->dev_conf.rxmode.max_rx_pkt_len);
 
 	if (rxmode->offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) {
-- 
2.7.4