Re: [PATCH 2/2] at76c50x-usb: set firmware and hardware version in wiphy

[Joerg Albert <jal2@gmx.de>]

On 09/24/2009 08:02 PM, Kalle Valo wrote:

> +	len = sizeof(wiphy->fw_version);
> +	snprintf(wiphy->fw_version, len, "%d.%d.%d-%d",
> +		 priv->fw_version.major, priv->fw_version.minor,
> +		 priv->fw_version.patch, priv->fw_version.build);
> +
> +	len = sizeof(wiphy->hw_version);
> +	snprintf(wiphy->hw_version, len, "%d", priv->board_type);
> +
> +	/* null terminate the strings in case they were truncated */
> +	wiphy->fw_version[len - 1] = '\0';
> +	wiphy->hw_version[len - 1] = '\0';

This only works as long as sizeof(wiphy->fw_version) == sizeof(wiphy->hw_version) - which is currently the case.
For sizeof(wiphy->fw_version) < sizeof(wiphy_hw_version) it overwrites memory behind wiphy->fw_version.

IMHO this is more robust against changes in the lengths of the char arrays:

+	wiphy->fw_version[sizeof(wiphy->fw_version) - 1] = '\0';
+	wiphy->hw_version[sizeof(wiphy->hw_version) - 1] = '\0';


Regards,
Jörg.