Re: [PATCH v2] PCI/sysfs: Change read permissions for VPD attributes

[Jean Delvare]

Hi Leon,

On Wed, 13 Nov 2024 14:59:58 +0200, Leon Romanovsky wrote:
> --- a/drivers/pci/vpd.c
> +++ b/drivers/pci/vpd.c
> @@ -332,6 +332,14 @@ static umode_t vpd_attr_is_visible(struct kobject *kobj,
>  	if (!pdev->vpd.cap)
>  		return 0;
>  
> +	/*
> +	 * Mellanox devices have implementation that allows VPD read by
> +	 * unprivileged users, so just add needed bits to allow read.
> +	 */
> +	WARN_ON_ONCE(a->attr.mode != 0600);
> +	if (unlikely(pdev->vendor == PCI_VENDOR_ID_MELLANOX))
> +		return a->attr.mode + 0044;

When manipulating bitfields, | is preferred. This would make the
operation safe regardless of the initial value, so you can even get rid
of the WARN_ON_ONCE() above.

> +
>  	return a->attr.mode;
>  }
>  

-- 
Jean Delvare
SUSE L3 Support