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From:   Wells Lu <wellslutw@gmail.com>
To:     linus.walleij@linaro.org, linux-gpio@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     wells.lu@sunplus.com, Wells Lu <wellslutw@gmail.com>
Subject: [PATCH v2] pinctrl:sunplus: Add check for kmalloc
Date:   Sun, 28 May 2023 20:34:37 +0800
Message-Id: <1685277277-12209-1-git-send-email-wellslutw@gmail.com>
Precedence: bulk

Fix Smatch static checker warning:
potential null dereference 'configs'. (kmalloc returns null)

Changes in v2:
1. Add free allocated memory before returned -ENOMEM.
2. Add call of_node_put() before returned -ENOMEM.

Fixes: aa74c44be19c ("pinctrl: Add driver for Sunplus SP7021")
Signed-off-by: Wells Lu <wellslutw@gmail.com>
---
 drivers/pinctrl/sunplus/sppctl.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/sunplus/sppctl.c b/drivers/pinctrl/sunplus/sppctl.c
index 6bbbab3..e91ce5b 100644
--- a/drivers/pinctrl/sunplus/sppctl.c
+++ b/drivers/pinctrl/sunplus/sppctl.c
@@ -834,11 +834,6 @@ static int sppctl_dt_node_to_map(struct pinctrl_dev *pctldev, struct device_node
 	int i, size = 0;
 
 	list = of_get_property(np_config, "sunplus,pins", &size);
-
-	if (nmG <= 0)
-		nmG = 0;
-
-	parent = of_get_parent(np_config);
 	*num_maps = size / sizeof(*list);
 
 	/*
@@ -866,10 +861,14 @@ static int sppctl_dt_node_to_map(struct pinctrl_dev *pctldev, struct device_node
 		}
 	}
 
+	if (nmG <= 0)
+		nmG = 0;
+
 	*map = kcalloc(*num_maps + nmG, sizeof(**map), GFP_KERNEL);
-	if (*map == NULL)
+	if (!(*map))
 		return -ENOMEM;
 
+	parent = of_get_parent(np_config);
 	for (i = 0; i < (*num_maps); i++) {
 		dt_pin = be32_to_cpu(list[i]);
 		pin_num = FIELD_GET(GENMASK(31, 24), dt_pin);
@@ -883,6 +882,8 @@ static int sppctl_dt_node_to_map(struct pinctrl_dev *pctldev, struct device_node
 			(*map)[i].data.configs.num_configs = 1;
 			(*map)[i].data.configs.group_or_pin = pin_get_name(pctldev, pin_num);
 			configs = kmalloc(sizeof(*configs), GFP_KERNEL);
+			if (!configs)
+				goto sppctl_map_err;
 			*configs = FIELD_GET(GENMASK(7, 0), dt_pin);
 			(*map)[i].data.configs.configs = configs;
 
@@ -896,6 +897,8 @@ static int sppctl_dt_node_to_map(struct pinctrl_dev *pctldev, struct device_node
 			(*map)[i].data.configs.num_configs = 1;
 			(*map)[i].data.configs.group_or_pin = pin_get_name(pctldev, pin_num);
 			configs = kmalloc(sizeof(*configs), GFP_KERNEL);
+			if (!configs)
+				goto sppctl_map_err;
 			*configs = SPPCTL_IOP_CONFIGS;
 			(*map)[i].data.configs.configs = configs;
 
@@ -965,6 +968,15 @@ static int sppctl_dt_node_to_map(struct pinctrl_dev *pctldev, struct device_node
 	of_node_put(parent);
 	dev_dbg(pctldev->dev, "%d pins mapped\n", *num_maps);
 	return 0;
+
+sppctl_map_err:
+	for (i = 0; i < (*num_maps); i++)
+		if (((*map)[i].type == PIN_MAP_TYPE_CONFIGS_PIN) &&
+		    (*map)[i].data.configs.configs)
+			kfree((*map)[i].data.configs.configs);
+	kfree(*map);
+	of_node_put(parent);
+	return -ENOMEM;
 }
 
 static const struct pinctrl_ops sppctl_pctl_ops = {
-- 
2.7.4