[PATCH v2] pinctrl:sunplus: Add check for kmalloc

From: Wells Lu
Date: Sun May 28 2023 - 08:35:28 EST


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@xxxxxxxxx>
---
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