driver core: platform: Prevent resouce overflow from causing infinite loops

num_resources in the platform_device struct is declared as a u32.  The
for loops that iterate over num_resources use an int as the counter,
which can cause infinite loops on architectures with smaller ints.
Change the loop counters to u32.

Signed-off-by: Simon Schwartz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Simon Schwartz

drivers/base/platform.c

@@ -27,6 +27,7 @@
 #include <linux/limits.h>
 #include <linux/property.h>
 #include <linux/kmemleak.h>
+#include <linux/types.h>
 
 #include "base.h"
 #include "power/power.h"
@@ -48,7 +49,7 @@ EXPORT_SYMBOL_GPL(platform_bus);
 struct resource *platform_get_resource(struct platform_device *dev,
 				       unsigned int type, unsigned int num)
 {
-	int i;
+	u32 i;
 
 	for (i = 0; i < dev->num_resources; i++) {
 		struct resource *r = &dev->resource[i];
@@ -255,7 +256,7 @@ struct resource *platform_get_resource_byname(struct platform_device *dev,
 					      unsigned int type,
 					      const char *name)
 {
-	int i;
+	u32 i;
 
 	for (i = 0; i < dev->num_resources; i++) {
 		struct resource *r = &dev->resource[i];
@@ -501,7 +502,8 @@ EXPORT_SYMBOL_GPL(platform_device_add_properties);
  */
 int platform_device_add(struct platform_device *pdev)
 {
-	int i, ret;
+	u32 i;
+	int ret;
 
 	if (!pdev)
 		return -EINVAL;
@@ -590,7 +592,7 @@ EXPORT_SYMBOL_GPL(platform_device_add);
  */
 void platform_device_del(struct platform_device *pdev)
 {
-	int i;
+	u32 i;
 
 	if (!IS_ERR_OR_NULL(pdev)) {
 		device_del(&pdev->dev);