Q: Given the following code slice:
```
1 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
3 	struct device_node *np = p->dev->of_node;
4 	int state, ret;
5 	char *propname;
6 	struct property *prop;
7 	const char *statename;
8 	const __be32 *list;
9 	int size, config;
10 	phandle phandle;
11 	struct device_node *np_config;
14 	if (!np) {
25 	for (state = 0; ; state++) {
27 		propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
28 		if (!propname)
30 		prop = of_find_property(np, propname, &size);
32 		if (!prop) {
39 		list = prop->value;
40 		size /= sizeof(*list);
43 		ret = of_property_read_string_index(np, "pinctrl-names",
50 		if (ret < 0)
51 			statename = prop->name + strlen("pinctrl-");
54 		for (config = 0; config < size; config++) {
55 			phandle = be32_to_cpup(list++);
58 			np_config = of_find_node_by_phandle(phandle);
59 			if (!np_config) {
68 			ret = dt_to_map_one_config(p, pctldev, statename,
71 			if (ret < 0)
76 		if (!size) {
77 			ret = dt_remember_dummy_state(p, statename);
78 			if (ret < 0)```
which has a CWE-476 vulnerability at line:
```
28 		if (!propname)
```
Please analyze the root cause of the vulnerability.