Re: [PATCH 3/3] alfred: properly initialize stack buffer before sending over unix socket

[Sven Eckelmann <sven@narfation.org>]

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On Wednesday, 12 January 2022 22:05:06 CET Marek Lindner wrote:
[...]
> diff --git a/client.c b/client.c
> index b5d8943..cf15ff4 100644
> --- a/client.c
> +++ b/client.c
> @@ -35,6 +35,7 @@ int alfred_client_request_data(struct globals *globals)
>  		return -1;
>  
>  	len = sizeof(request);
> +	memset(&request, 0, len);
>  
>  	request.header.type = ALFRED_REQUEST;
>  	request.header.version = ALFRED_VERSION;

All bytes (also all bits) are overwritten in the lines below the memset. So I 
don't see why memset would be required here.

> @@ -184,6 +185,7 @@ int alfred_client_modeswitch(struct globals *globals)
>  		return -1;
>  
>  	len = sizeof(modeswitch);
> +	memset(&modeswitch, 0, len);
>  
>  	modeswitch.header.type = ALFRED_MODESWITCH;
>  	modeswitch.header.version = ALFRED_VERSION;

Same here - with a minor exception. When mode is not written then the data is 
not written to the socket.

> @@ -260,6 +262,7 @@ int alfred_client_change_interface(struct globals *globals)
>  	}
>  
>  	len = sizeof(change_interface);
> +	memset(&change_interface, 0, len);
>  
>  	change_interface.header.type = ALFRED_CHANGE_INTERFACE;
>  	change_interface.header.version = ALFRED_VERSION;\

Same here.

> @@ -308,6 +311,7 @@ int alfred_client_change_bat_iface(struct globals *globals)
>  	}
>  
>  	len = sizeof(change_bat_iface);
> +	memset(&change_bat_iface, 0, len);
>  
>  	change_bat_iface.header.type = ALFRED_CHANGE_BAT_IFACE;
>  	change_bat_iface.header.version = ALFRED_VERSION;
> 

Same here.

Kind regards,
	Sven


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