[LTP] [PATCH 4/4] can_bcm01: Move vcan to .modprobe

[Richard Palethorpe]

Hello,

Petr Vorel <pvorel@suse.cz> writes:

> Signed-off-by: Petr Vorel <pvorel@suse.cz>
> ---
>  testcases/network/can/cve/can_bcm01.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/testcases/network/can/cve/can_bcm01.c b/testcases/network/can/cve/can_bcm01.c
> index d9a835b03..ec98db133 100644
> --- a/testcases/network/can/cve/can_bcm01.c
> +++ b/testcases/network/can/cve/can_bcm01.c
> @@ -41,14 +41,6 @@ static void setup(void)
>  {
>  	struct sockaddr_can addr = { .can_family = AF_CAN };
>  
> -	/*
> -	 * Older kernels require explicit modprobe of vcan. Newer kernels
> -	 * will load the modules automatically and support CAN in network
> -	 * namespace which would eliminate the need for running the test
> -	 * with root privileges.
> -	 */
> -	tst_cmd((const char*[]){"modprobe", "vcan", NULL}, NULL, NULL, 0);
> -
>  	NETDEV_ADD_DEVICE(LTP_DEVICE, "vcan");
>  	NETDEV_SET_STATE(LTP_DEVICE, 1);
>  	addr.can_ifindex = NETDEV_INDEX_BY_NAME(LTP_DEVICE);
> @@ -143,10 +135,19 @@ static struct tst_test test = {
>  	.skip_in_compat = 1,
>  	.max_runtime = 30,
>  	.needs_drivers = (const char *const[]) {
> -		"vcan",
>  		"can-bcm",
>  		NULL
>  	},
> +	/*
> +	 * Older kernels require explicit modprobe of vcan. Newer kernels
> +	 * will load the modules automatically and support CAN in network
> +	 * namespace which would eliminate the need for running the test
> +	 * with root privileges.
> +	 */

This comment is wrong and can be removed. It also (or only?) depends on
kernel config whether modules are loaded automatically. It is a security
feature to remove automatic modprobe. IDK if older kernels lacked auto
module loading.

> +	.modprobe = (const char *const[]) {
> +		"vcan",
> +		NULL
> +	},
>  	.tags = (const struct tst_tag[]) {
>  		{"linux-git", "d5f9023fa61e"},
>  		{"CVE", "2021-3609"},
> -- 
> 2.42.0


-- 
Thank you,
Richard.