Re: [PATCH v2 4/4] smack: provide socketpair callback

[Casey Schaufler]

On 5/4/2018 7:28 AM, David Herrmann wrote:
> From: Tom Gundersen <teg@xxxxxxx>
>
> Make sure to implement the new socketpair callback so the SO_PEERSEC
> call on socketpair(2)s will return correct information.
>
> Signed-off-by: Tom Gundersen <teg@xxxxxxx>
> Signed-off-by: David Herrmann <dh.herrmann@xxxxxxxxx>

This doesn't look like it will cause any problems.
I've only been able to test it in a general way. I
haven't created specific tests, but it passes the
usual Smack use cases.

Acked-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>

> ---
>  security/smack/smack_lsm.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 0b414836bebd..dcb976f98df2 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -2842,6 +2842,27 @@ static int smack_socket_post_create(struct socket *sock, int family,
>  	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
>  }
>  
> +/**
> + * smack_socket_socketpair - create socket pair
> + * @socka: one socket
> + * @sockb: another socket
> + *
> + * Cross reference the peer labels for SO_PEERSEC
> + *
> + * Returns 0 on success, and error code otherwise
> + */
> +static int smack_socket_socketpair(struct socket *socka,
> +		                   struct socket *sockb)
> +{
> +	struct socket_smack *asp = socka->sk->sk_security;
> +	struct socket_smack *bsp = sockb->sk->sk_security;
> +
> +	asp->smk_packet = bsp->smk_out;
> +	bsp->smk_packet = asp->smk_out;
> +
> +	return 0;
> +}
> +
>  #ifdef SMACK_IPV6_PORT_LABELING
>  /**
>   * smack_socket_bind - record port binding information.
> @@ -4724,6 +4745,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>  	LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
>  
>  	LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
> +	LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
>  #ifdef SMACK_IPV6_PORT_LABELING
>  	LSM_HOOK_INIT(socket_bind, smack_socket_bind),
>  #endif