[PATCH 22.11] net/hns3: fix overwrite mbuf in vector path

[Chengwen Feng <fengchengwen@huawei.com>]

[ upstream commit 06b296a2264fcd1fe2d167f2d90a58607f5e81f5 ]

The vector path processes multiple descriptors at a time and modifies
the corresponding mbufs accordingly. When the mbufs cannot be applied
for, the previous patch [1] only clears the first descriptor's valid
bit, which is not enough. In this patch, the mbufs points to the
fake_mbuf to prevent overwrite.

[1] commit 01843ab2f2fc ("net/hns3: fix crash for NEON and SVE")

Fixes: a3d4f4d291d7 ("net/hns3: support NEON Rx")
Fixes: 01843ab2f2fc ("net/hns3: fix crash for NEON and SVE")

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Signed-off-by: Dengdui Huang <huangdengdui@huawei.com>
---
 drivers/net/hns3/hns3_rxtx_vec.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/hns3/hns3_rxtx_vec.c b/drivers/net/hns3/hns3_rxtx_vec.c
index 2265804fda..1af064e77f 100644
--- a/drivers/net/hns3/hns3_rxtx_vec.c
+++ b/drivers/net/hns3/hns3_rxtx_vec.c
@@ -69,8 +69,12 @@ hns3_rxq_rearm_mbuf(struct hns3_rx_queue *rxq)
 		/*
 		 * Clear VLD bit for the first descriptor rearmed in case
 		 * of going to receive packets later.
+		 * And also point mbufs to fake_mbuf to prevent modification
+		 * of the mbuf field during vector packet receiving.
 		 */
 		rxdp[0].rx.bd_base_info = 0;
+		for (i = 0; i < HNS3_VECTOR_RX_OFFSET_TABLE_LEN; i++)
+			rxep[i].mbuf = &rxq->fake_mbuf;
 		rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed++;
 		return;
 	}
-- 
2.17.1