[PATCH] selinux: remove redundant selinux_nlmsg_perm

[Stephen Smalley]

On 1/12/20 10:42 AM, Huaisheng Ye wrote:
> From: Huaisheng Ye <yehs1 at lenovo.com>
> 
> selinux_nlmsg_perm is used for only by selinux_netlink_send. Remove
> the redundant function to simplify the code.
> 
> Signed-off-by: Huaisheng Ye <yehs1 at lenovo.com>

The patch itself seems fine but it looks like someone accidentally put 
pig= in the log message when they meant pid=; that can be fixed via a 
separate patch.

Acked-by: Stephen Smalley <sds at tycho.nsa.gov>

> ---
>   security/selinux/hooks.c | 73 ++++++++++++++++++++++--------------------------
>   1 file changed, 34 insertions(+), 39 deletions(-)
> 
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index fb1b9da..9f3f966 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -5507,44 +5507,6 @@ static int selinux_tun_dev_open(void *security)
>   	return 0;
>   }
>   
> -static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
> -{
> -	int err = 0;
> -	u32 perm;
> -	struct nlmsghdr *nlh;
> -	struct sk_security_struct *sksec = sk->sk_security;
> -
> -	if (skb->len < NLMSG_HDRLEN) {
> -		err = -EINVAL;
> -		goto out;
> -	}
> -	nlh = nlmsg_hdr(skb);
> -
> -	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
> -	if (err) {
> -		if (err == -EINVAL) {
> -			pr_warn_ratelimited("SELinux: unrecognized netlink"
> -			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
> -			       " pig=%d comm=%s\n",
> -			       sk->sk_protocol, nlh->nlmsg_type,
> -			       secclass_map[sksec->sclass - 1].name,
> -			       task_pid_nr(current), current->comm);
> -			if (!enforcing_enabled(&selinux_state) ||
> -			    security_get_allow_unknown(&selinux_state))
> -				err = 0;
> -		}
> -
> -		/* Ignore */
> -		if (err == -ENOENT)
> -			err = 0;
> -		goto out;
> -	}
> -
> -	err = sock_has_perm(sk, perm);
> -out:
> -	return err;
> -}
> -
>   #ifdef CONFIG_NETFILTER
>   
>   static unsigned int selinux_ip_forward(struct sk_buff *skb,
> @@ -5873,7 +5835,40 @@ static unsigned int selinux_ipv6_postroute(void *priv,
>   
>   static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
>   {
> -	return selinux_nlmsg_perm(sk, skb);
> +	int err = 0;
> +	u32 perm;
> +	struct nlmsghdr *nlh;
> +	struct sk_security_struct *sksec = sk->sk_security;
> +
> +	if (skb->len < NLMSG_HDRLEN) {
> +		err = -EINVAL;
> +		goto out;
> +	}
> +	nlh = nlmsg_hdr(skb);
> +
> +	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
> +	if (err) {
> +		if (err == -EINVAL) {
> +			pr_warn_ratelimited("SELinux: unrecognized netlink"
> +			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
> +			       " pig=%d comm=%s\n",
> +			       sk->sk_protocol, nlh->nlmsg_type,
> +			       secclass_map[sksec->sclass - 1].name,
> +			       task_pid_nr(current), current->comm);
> +			if (!enforcing_enabled(&selinux_state) ||
> +			    security_get_allow_unknown(&selinux_state))
> +				err = 0;
> +		}
> +
> +		/* Ignore */
> +		if (err == -ENOENT)
> +			err = 0;
> +		goto out;
> +	}
> +
> +	err = sock_has_perm(sk, perm);
> +out:
> +	return err;
>   }
>   
>   static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
>