Re: [PATCH v3 7/9] vdpa: solidrun: Fix UB bug with devres

[Andy Shevchenko <andy@kernel.org>]

On Thu, Aug 22, 2024 at 03:47:39PM +0200, Philipp Stanner wrote:
> In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed to
> pcim_iomap_regions() is placed on the stack. Neither
> pcim_iomap_regions() nor the functions it calls copy that string.
> 
> Should the string later ever be used, this, consequently, causes
> undefined behavior since the stack frame will by then have disappeared.
> 
> Fix the bug by allocating the strings on the heap through
> devm_kasprintf().

...

> -	snprintf(name, sizeof(name), "psnet[%s]-bars", pci_name(pdev));
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> +	if (!name)
> +		return -ENOMEM;
> +
>  	ret = pcim_iomap_regions(pdev, mask, name);

...

> -	snprintf(name, sizeof(name), "snet[%s]-bar", pci_name(pdev));
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> +	if (!name)
> +		return -ENOMEM;

+ Blank line as in the above snippet?

>  	/* Request and map BAR */
>  	ret = pcim_iomap_regions(pdev, BIT(snet->psnet->cfg.vf_bar), name);

-- 
With Best Regards,
Andy Shevchenko