[PATCH v2 2/2] net/netvsc: fix race condition in RNDIS command execution

[madhukar.mythri at gmail.com]

From: Madhuker Mythri <madhukar.mythri at gmail.com>

When multiple threads issue RNDIS command requests (such as device
info queries and link status checks) simultaneously, command failures
can occur due to concurrent access to shared resources in the RNDIS
execution path.

Add a spinlock to serialize RNDIS command execution and prevent
data corruption.

Fixes: 4e9c73e96e83 ("net/netvsc: add Hyper-V network device")
Cc: stable at dpdk.org

Signed-off-by: Madhuker Mythri <madhukar.mythri at gmail.com>
---
 drivers/net/netvsc/hn_ethdev.c | 1 +
 drivers/net/netvsc/hn_rndis.c  | 2 ++
 drivers/net/netvsc/hn_var.h    | 1 +
 3 files changed, 4 insertions(+)

diff --git a/drivers/net/netvsc/hn_ethdev.c b/drivers/net/netvsc/hn_ethdev.c
index 6584819f4f..b525e287fa 100644
--- a/drivers/net/netvsc/hn_ethdev.c
+++ b/drivers/net/netvsc/hn_ethdev.c
@@ -1310,6 +1310,7 @@ eth_hn_dev_init(struct rte_eth_dev *eth_dev)
 	PMD_INIT_FUNC_TRACE();
 
 	rte_spinlock_init(&hv->hotadd_lock);
+	rte_spinlock_init(&hv->cmd_lock);
 	LIST_INIT(&hv->hotadd_list);
 
 	vmbus = container_of(device, struct rte_vmbus_device, device);
diff --git a/drivers/net/netvsc/hn_rndis.c b/drivers/net/netvsc/hn_rndis.c
index 7c54eebcef..8a0716df89 100644
--- a/drivers/net/netvsc/hn_rndis.c
+++ b/drivers/net/netvsc/hn_rndis.c
@@ -500,8 +500,10 @@ hn_rndis_query(struct hn_data *hv, uint32_t oid,
 	/* Input data immediately follows RNDIS query. */
 	memcpy(req + 1, idata, idlen);
 
+	rte_spinlock_lock(&hv->cmd_lock);
 	error = hn_rndis_execute(hv, rid, req, reqlen,
 				 comp, comp_len, RNDIS_QUERY_CMPLT);
+	rte_spinlock_unlock(&hv->cmd_lock);
 
 	if (error)
 		goto done;
diff --git a/drivers/net/netvsc/hn_var.h b/drivers/net/netvsc/hn_var.h
index 17c1d5d07b..66ed186c0a 100644
--- a/drivers/net/netvsc/hn_var.h
+++ b/drivers/net/netvsc/hn_var.h
@@ -179,6 +179,7 @@ struct hn_data {
 	struct vmbus_channel *channels[HN_MAX_CHANNELS];
 
 	rte_spinlock_t	hotadd_lock;
+	rte_spinlock_t	cmd_lock;
 	LIST_HEAD(hotadd_list, hv_hotadd_context) hotadd_list;
 };
 
-- 
2.50.1 (Apple Git-155)