[dpdk-dev] [PATCH 1/9] net/pcap: fix argument checks

[Kevin Traynor <ktraynor@redhat.com>]

Previously rx/tx_queues were passed into eth_from_pcaps_common()
as ptrs and were checked for being NULL.

In commit da6ba28f0540 ("net/pcap: use a struct to pass user options")
that changed to pass in a ptr to a pmd_devargs_all which contains
the rx/tx_queues.

The parameter checking was not updated as part of that commit and
coverity caught that there was still a check if rx/tx_queues were
NULL, apparently after they had been dereferenced.

Fix that by checking the pmd_devargs_all ptr and removing the NULL
checks on rx/tx_queues.

1231        struct pmd_devargs *rx_queues = &devargs_all->rx_queues;
1232        struct pmd_devargs *tx_queues = &devargs_all->tx_queues;
1233        const unsigned int nb_rx_queues = rx_queues->num_of_queue;
    deref_ptr: Directly dereferencing pointer tx_queues.
1234        const unsigned int nb_tx_queues = tx_queues->num_of_queue;
1235        unsigned int i;
1236
1237        /* do some parameter checking */
    CID 345004: Dereference before null check (REVERSE_INULL)
    [select issue]
1238        if (rx_queues == NULL && nb_rx_queues > 0)
1239                return -1;
    CID 345029 (#1 of 1): Dereference before null check (REVERSE_INULL)
    check_after_deref: Null-checking tx_queues suggests that it may be
    null, but it has already been dereferenced on all paths leading to
    the check.
1240        if (tx_queues == NULL && nb_tx_queues > 0)
1241                return -1;

Coverity issue: 345029
Coverity issue: 345044
Fixes: da6ba28f0540 ("net/pcap: use a struct to pass user options")
Cc: cian.ferriter@intel.com
Cc: stable@dpdk.org

Signed-off-by: Kevin Traynor <ktraynor@redhat.com>
---
 drivers/net/pcap/rte_eth_pcap.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
index 5489010b6..7cf00306e 100644
--- a/drivers/net/pcap/rte_eth_pcap.c
+++ b/drivers/net/pcap/rte_eth_pcap.c
@@ -1229,16 +1229,19 @@ eth_from_pcaps_common(struct rte_vdev_device *vdev,
 {
 	struct pmd_process_private *pp;
-	struct pmd_devargs *rx_queues = &devargs_all->rx_queues;
-	struct pmd_devargs *tx_queues = &devargs_all->tx_queues;
-	const unsigned int nb_rx_queues = rx_queues->num_of_queue;
-	const unsigned int nb_tx_queues = tx_queues->num_of_queue;
+	struct pmd_devargs *rx_queues;
+	struct pmd_devargs *tx_queues;
+	unsigned int nb_rx_queues;
+	unsigned int nb_tx_queues;
 	unsigned int i;
 
-	/* do some parameter checking */
-	if (rx_queues == NULL && nb_rx_queues > 0)
-		return -1;
-	if (tx_queues == NULL && nb_tx_queues > 0)
+	if (devargs_all == NULL)
 		return -1;
 
+	rx_queues = &devargs_all->rx_queues;
+	tx_queues = &devargs_all->tx_queues;
+
+	nb_rx_queues = rx_queues->num_of_queue;
+	nb_tx_queues = tx_queues->num_of_queue;
+
 	if (pmd_init_internals(vdev, nb_rx_queues, nb_tx_queues, internals,
 			eth_dev) < 0)
-- 
2.21.0