[PATCH 1/2] common/mlx5: fix miss null check in devargs parsing

[Michael Baum]

The common MLX5 probe function parses first the devargs and save them in
a dictionary.
It gets structure called "devargs" as a member of EAL device containing
all needed information.

When "devargs" structure is invalid, the function avoids parsing it.
However, when it valid but its field "args" is invalid, the function
tries to parse it and dereference to NULL pointer.

This patch adds check to avoid this NULL dereferencing.

Fixes: a729d2f093e9 ("common/mlx5: refactor devargs management")
Cc: michaelba at nvidia.com
Cc: stable at dpdk.org

Signed-off-by: Michael Baum <michaelba at nvidia.com>
Acked-by: Matan Azrad <matan at nvidia.com>
---
 drivers/common/mlx5/mlx5_common.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/common/mlx5/mlx5_common.c b/drivers/common/mlx5/mlx5_common.c
index 4dcc8cc49c..bf22c0694d 100644
--- a/drivers/common/mlx5/mlx5_common.c
+++ b/drivers/common/mlx5/mlx5_common.c
@@ -164,8 +164,9 @@ mlx5_kvargs_prepare(struct mlx5_kvargs_ctrl *mkvlist,
 	struct rte_kvargs *kvlist;
 	uint32_t i;
 
-	if (devargs == NULL)
+	if (mkvlist == NULL)
 		return 0;
+	MLX5_ASSERT(devargs != NULL && devargs->args != NULL);
 	kvlist = rte_kvargs_parse(devargs->args, NULL);
 	if (kvlist == NULL) {
 		rte_errno = EINVAL;
@@ -400,8 +401,9 @@ parse_class_options(const struct rte_devargs *devargs,
 {
 	int ret = 0;
 
-	if (devargs == NULL)
+	if (mkvlist == NULL)
 		return 0;
+	MLX5_ASSERT(devargs != NULL);
 	if (devargs->cls != NULL && devargs->cls->name != NULL)
 		/* Global syntax, only one class type. */
 		return class_name_to_value(devargs->cls->name);
@@ -965,7 +967,7 @@ mlx5_common_dev_probe(struct rte_device *eal_dev)
 	int ret;
 
 	DRV_LOG(INFO, "probe device \"%s\".", eal_dev->name);
-	if (eal_dev->devargs != NULL)
+	if (eal_dev->devargs != NULL && eal_dev->devargs->args != NULL)
 		mkvlist_p = &mkvlist;
 	ret = mlx5_kvargs_prepare(mkvlist_p, eal_dev->devargs);
 	if (ret < 0) {
-- 
2.25.1