Re: [PATCH] nvdimm: Replace the usage of a variable by a direct function call in nd_pfn_validate()

[Andy Shevchenko]

On Fri, Apr 14, 2023 at 12:12:37PM +0200, Markus Elfring wrote:
> Date: Fri, 14 Apr 2023 12:01:15 +0200
> 
> The address of a data structure member was determined before
> a corresponding null pointer check in the implementation of
> the function “nd_pfn_validate”.
> 
> Thus avoid the risk for undefined behaviour by replacing the usage of
> the local variable “parent_uuid” by a direct function call within
> a later condition check.

> This issue was detected by using the Coccinelle software.
> 
> Fixes: d1c6e08e7503649e4a4f3f9e700e2c05300b6379 ("libnvdimm/labels: Add uuid helpers")

Same issues as per patch 1.

...

> -	if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
> +	if (memcmp(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16) != 0)

If parent_uuid is of uuid_t type, you better to replace memcmp() with
uuid_equal().

>  		return -ENODEV;

-- 
With Best Regards,
Andy Shevchenko