[dpdk-dev] [PATCH] net/bnxt: fix a possible stack smashing

[Yuan Linsi <yuanlinsi01@baidu.com>]

From: Linsi Yuan <yuanlinsi01@baidu.com>

We see a stack smashing as a result of defensive code missing. Once the
nb_pkts is less than RTE_BNXT_DESCS_PER_LOOP, it will be modified to
zero after doing a floor align, and we can not exit the following
receiving packets loop. And the buffers will be overwrite, then the
stack frame was ruined.

Fix the problem by adding defensive code, once the nb_pkts is zero, just
directly return with no packets.

Fixes: bc4a000f2 ("net/bnxt: implement SSE vector mode")
Cc: stable@dpdk.org

Signed-off-by: Linsi Yuan <yuanlinsi01@baidu.com>
Signed-off-by: Dongsheng Rong <rongdongsheng@baidu.com>
---
 drivers/net/bnxt/bnxt_rxtx_vec_sse.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bnxt/bnxt_rxtx_vec_sse.c b/drivers/net/bnxt/bnxt_rxtx_vec_sse.c
index d0e7910e7..8f73add9b 100644
--- a/drivers/net/bnxt/bnxt_rxtx_vec_sse.c
+++ b/drivers/net/bnxt/bnxt_rxtx_vec_sse.c
@@ -233,8 +233,13 @@ bnxt_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 	/* Return no more than RTE_BNXT_MAX_RX_BURST per call. */
 	nb_pkts = RTE_MIN(nb_pkts, RTE_BNXT_MAX_RX_BURST);
 
-	/* Make nb_pkts an integer multiple of RTE_BNXT_DESCS_PER_LOOP */
+	/*
+	 * Make nb_pkts an integer multiple of RTE_BNXT_DESCS_PER_LOOP.
+	 * nb_pkts < RTE_BNXT_DESCS_PER_LOOP, just return no packet
+	 */
 	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_BNXT_DESCS_PER_LOOP);
+	if (!nb_pkts)
+		return 0;
 
 	/* Handle RX burst request */
 	while (1) {
-- 
2.11.0