[PATCH net] ice: Add check for kzalloc

[Jiasheng Jiang]

As kzalloc may fail and return NULL pointer,
it should be better to check the return value
in order to avoid the NULL pointer dereference.

Fixes: d6b98c8d242a ("ice: add write functionality for GNSS TTY")
Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
---
 drivers/net/ethernet/intel/ice/ice_gnss.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c
index b5a7f246d230..6d3d5e75726b 100644
--- a/drivers/net/ethernet/intel/ice/ice_gnss.c
+++ b/drivers/net/ethernet/intel/ice/ice_gnss.c
@@ -421,7 +421,7 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf)
 	const int ICE_TTYDRV_NAME_MAX = 14;
 	struct tty_driver *tty_driver;
 	char *ttydrv_name;
-	unsigned int i;
+	unsigned int i, j;
 	int err;
 
 	tty_driver = tty_alloc_driver(ICE_GNSS_TTY_MINOR_DEVICES,
@@ -462,6 +462,17 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf)
 					       GFP_KERNEL);
 		pf->gnss_serial[i] = NULL;
 
+		if (!pf->gnss_tty_port[i]) {
+			for (j = 0; j < i; j++) {
+				tty_port_destroy(pf->gnss_tty_port[j]);
+				kfree(pf->gnss_tty_port[j]);
+			}
+			kfree(ttydrv_name);
+			tty_driver_kref_put(pf->ice_gnss_tty_driver);
+
+			return NULL;
+		}
+
 		tty_port_init(pf->gnss_tty_port[i]);
 		tty_port_link_device(pf->gnss_tty_port[i], tty_driver, i);
 	}
-- 
2.25.1