From cbouatmailru@gmail.com Tue Sep 21 13:28:07 2010 Date: Tue, 7 Sep 2010 17:31:49 +0400 From: Anton Vorontsov To: Greg Kroah-Hartman Cc: Samuel Ortiz , Mark Brown , linux-kernel@vger.kernel.org Subject: base/platform: Safe handling for NULL platform data and resources Message-ID: <20100907133149.GA28139@oksana.dev.rtsoft.ru> Content-Disposition: inline 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 Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -192,6 +192,9 @@ int platform_device_add_resources(struct { 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_re 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;