[PATCH 2/2] net/sfc: fix a Tx queue double release possibility

[Andrew Rybchenko <arybchenko@solarflare.com>]

From: Igor Romanov <igor.romanov@oktetlabs.ru>

There are two function that call sfc_tx_qfini():
sfc_tx_fini_queues() and sfc_tx_queue_release(). But only
sfc_tx_queue_release() sets tx_queues pointer of the device data to NULL.
It may lead to the scenario in which a queue is destroyed by
sfc_tx_fini_queues() and after the queue is attempted to be destroyed again
by sfc_tx_queue_release().

Move NULL assignment to sfc_tx_qfini().

Fixes: b1b7ad933b39 ("net/sfc: set up and release Tx queues")
Cc: stable@dpdk.org

Signed-off-by: Igor Romanov <igor.romanov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 drivers/net/sfc/sfc_ethdev.c | 3 ---
 drivers/net/sfc/sfc_tx.c     | 2 ++
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index 23778c9f3..93bfecc4e 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -498,9 +498,6 @@ sfc_tx_queue_release(void *queue)
 
 	sfc_adapter_lock(sa);
 
-	SFC_ASSERT(sw_index < sa->eth_dev->data->nb_tx_queues);
-	sa->eth_dev->data->tx_queues[sw_index] = NULL;
-
 	sfc_tx_qfini(sa, sw_index);
 
 	sfc_adapter_unlock(sa);
diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index 8af08b37c..12665d813 100644
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -233,6 +233,8 @@ sfc_tx_qfini(struct sfc_adapter *sa, unsigned int sw_index)
 	sfc_log_init(sa, "TxQ = %u", sw_index);
 
 	SFC_ASSERT(sw_index < sa->txq_count);
+	sa->eth_dev->data->tx_queues[sw_index] = NULL;
+
 	txq_info = &sa->txq_info[sw_index];
 
 	txq = txq_info->txq;
-- 
2.17.1