Re: [PATCH] can: test size of struct sockaddr

[Oliver Hartkopp <socketcan-fJ+pQTUTwRTk1uMJSBkQmQ@public.gmane.org>]

On 14.01.2011 18:23, Kurt Van Dijck wrote:
> I think this patch makes the CAN socket code comform to the
> manpages of sendmsg & recvmsg.

Hello Kurt,

if you check similar code sniplets in the kernel you would see, that in
recvmsg()-cases the given namelen is not used from userspace.

If msg->msg_name is not NULL the msg_namelen is just set by the kernel. E.g.
see af_packet.c, af_econet.c, etc.

So the code in candump.c setting the msg_namelen before recvmsg() is obviously
obsolete ...

Btw. your two patches below for bcm_sendmsg() and raw_sendmesg() look good.

If you would like to resubmit these two patches, you may add my Acked-by

Thanks,
Oliver



> diff --git a/net/can/bcm.c b/net/can/bcm.c
> index 6faa825..dc0d5d6 100644
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -1256,6 +1256,9 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
>  		struct sockaddr_can *addr =
>  			(struct sockaddr_can *)msg->msg_name;
>  
> +		if (msg->msg_namelen < sizeof(*addr))
> +			return -EINVAL;
> +
>  		if (addr->can_family != AF_CAN)
>  			return -EINVAL;
>  


> diff --git a/net/can/raw.c b/net/can/raw.c
> index e88f610..e68a6d3 100644
> --- a/net/can/raw.c
> +++ b/net/can/raw.c
> @@ -649,6 +649,9 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
>  		struct sockaddr_can *addr =
>  			(struct sockaddr_can *)msg->msg_name;
>  
> +		if (msg->msg_namelen < sizeof(*addr))
> +			return -EINVAL;
> +
>  		if (addr->can_family != AF_CAN)
>  			return -EINVAL;
>