[PATCH 5.4 218/344] driver core: platform: Prevent resouce overflow from causing infinite loops

Greg Kroah-Hartman
2020-02-21T08:12:57Z

From: Simon Schwartz <kern.simon@theschwartz.xyz>

[ Upstream commit 39cc539f90d035a293240c9443af50be55ee81b8 ]

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 <kern.simon@theschwartz.xyz>
Link: https://lore.kernel.org/r/2201ce63a2a171ffd2ed14e867875316efcf71db.camel@theschwartz.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/platform.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 3c0cd20925b71..ee99b15581290 100644
--- a/drivers/base/platform.c
+++ b/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];
@@ -226,7 +227,7 @@ 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];
@@ -473,7 +474,8 @@ 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;
@@ -562,7 +564,7 @@ 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);
--
2.20.1