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Subject[PATCH 1/2] base/platform: Safe handling for NULL platform data and resources
Some users of platform_device_add_{data,resources}() assume that
NULL data and resources will be handled specially, i.e. just ignored.

But the platform core ends up calling kmemdup(NULL, 0, ...), which
returns a non-NULL result (i.e. ZERO_SIZE_PTR), which causes drivers
to oops on a valid code, something like:

if (platform_data)
stuff = platform_data->stuff;

This patch makes the platform core a bit more safe for such cases.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
---
drivers/base/platform.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index c6c933f..67519cd 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -192,6 +192,9 @@ int platform_device_add_resources(struct platform_device *pdev,
{
struct resource *r;

+ if (!res)
+ return 0;
+
r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
if (r) {
pdev->resource = r;
@@ -215,8 +218,12 @@ EXPORT_SYMBOL_GPL(platform_device_add_resources);
int platform_device_add_data(struct platform_device *pdev, const void *data,
size_t size)
{
- void *d = kmemdup(data, size, GFP_KERNEL);
+ void *d;
+
+ if (!data)
+ return 0;

+ d = kmemdup(data, size, GFP_KERNEL);
if (d) {
pdev->dev.platform_data = d;
return 0;
--
1.7.0.5


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