[PATCH net-next] net: macb: Validate the value of base_time properly

[Chandra Mohan Sundar <chandramohan.explore@gmail.com>]

In macb_taprio_setup_replace(), the value of start_time is being
compared against zero which would never be true since start_time
is an unsigned value. Due to this there is a chance that an
incorrect config base time value can be used for computation.

Fix by checking the value of conf->base_time directly.
This issue was reported by static coverity analyzer.

Fixes: 89934dbf169e3 ("net: macb: Add TAPRIO traffic scheduling support")
Signed-off-by: Chandra Mohan Sundar <chandramohan.explore@gmail.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 290d67da704d..e9b262a0223f 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4104,7 +4104,7 @@ static int macb_taprio_setup_replace(struct net_device *ndev,
 		return -EINVAL;
 	}
 
-	if (start_time < 0) {
+	if (conf->base_time < 0) {
 		netdev_err(ndev, "Invalid base_time: must be 0 or positive, got %lld\n",
 			   conf->base_time);
 		return -ERANGE;
-- 
2.43.0