device property: avoid allocations of 0 length

Arrays can not have zero elements by definition of the unified device
properties. If such property comes from outside we should not allow it to pass.
Otherwise memory allocation on 0 length will return non-NULL value, which we
currently don't check.

Prevent memory allocations of 0 length.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/property.c

@@ -653,6 +653,9 @@ int fwnode_property_match_string(struct fwnode_handle *fwnode,
 	if (nval < 0)
 		return nval;
 
+	if (nval == 0)
+		return -ENODATA;
+
 	values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
 	if (!values)
 		return -ENOMEM;
@@ -718,6 +721,9 @@ static int pset_copy_entry(struct property_entry *dst,
 		return -ENOMEM;
 
 	if (src->is_array) {
+		if (!src->length)
+			return -ENODATA;
+
 		if (src->is_string) {
 			nval = src->length / sizeof(const char *);
 			dst->pointer.str = kcalloc(nval, sizeof(const char *),