[dpdk-stable] [PATCH v2] ethdev: limit maximum number of queues

[Thomas Monjalon]

A buffer overflow happens in testpmd with some drivers
since the queue arrays are limited to RTE_MAX_QUEUES_PER_PORT.

The advertised capabilities of mlx4, mlx5 and softnic
for the number of queues were the maximum number: UINT16_MAX.
They must be limited by the configured RTE_MAX_QUEUES_PER_PORT
that applications expect to be respected.

The limitation is applied at ethdev level (function rte_eth_dev_info_get),
in order to force the configured limit for all drivers.

Fixes: 14b53e27b30e ("ethdev: fix crash with multiprocess")
Cc: stable at dpdk.org

Reported-by: Raslan Darawsheh <rasland at mellanox.com>
Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>
---
v2: remove changes in drivers, keep limit only in ethdev
---
 lib/librte_ethdev/rte_ethdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 8d2ce31a81..6e9cb243ea 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -2986,6 +2986,12 @@ rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)
 		return eth_err(port_id, diag);
 	}
 
+	/* Maximum number of queues should be <= RTE_MAX_QUEUES_PER_PORT */
+	dev_info->max_rx_queues = RTE_MIN(dev_info->max_rx_queues,
+			RTE_MAX_QUEUES_PER_PORT);
+	dev_info->max_tx_queues = RTE_MIN(dev_info->max_tx_queues,
+			RTE_MAX_QUEUES_PER_PORT);
+
 	dev_info->driver_name = dev->device->driver->name;
 	dev_info->nb_rx_queues = dev->data->nb_rx_queues;
 	dev_info->nb_tx_queues = dev->data->nb_tx_queues;
-- 
2.23.0