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Date:   Sun, 24 May 2020 17:57:32 -0600
From:   Tycho Andersen <tycho@tycho.ws>
To:     Sargun Dhillon <sargun@sargun.me>
Cc:     linux-kernel@vger.kernel.org,
        containers@lists.linux-foundation.org, linux-api@vger.kernel.org,
        christian.brauner@ubuntu.com, keescook@chromium.org,
        cyphar@cyphar.com, Jeffrey Vander Stoep <jeffv@google.com>,
        jannh@google.com, rsesek@google.com, palmer@google.com,
        Matt Denton <mpdenton@google.com>,
        Kees Cook <keescook@google.com>
Subject: Re: [PATCH 2/5] seccomp: Introduce addfd ioctl to seccomp user
 notifier
Message-ID: <20200524235732.GI2605652@cisco>
References: <20200524233942.8702-1-sargun@sargun.me>
 <20200524233942.8702-3-sargun@sargun.me>
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On Sun, May 24, 2020 at 04:39:39PM -0700, Sargun Dhillon wrote:
> +static void seccomp_handle_addfd(struct seccomp_kaddfd *addfd)
> +{
> +	int ret;
> +
> +	/*
> +	 * Remove the notification, and reset the list pointers, indicating
> +	 * that it has been handled.
> +	 */
> +	list_del_init(&addfd->list);
> +
> +	ret = security_file_receive(addfd->file);
> +	if (ret)
> +		goto out;
> +
> +	if (addfd->fd >= 0) {
> +		ret = replace_fd(addfd->fd, addfd->file, addfd->flags);
> +		if (ret >= 0)
> +			fput(addfd->file);
> +	} else {
> +		ret = get_unused_fd_flags(addfd->flags);
> +		if (ret >= 0)
> +			fd_install(ret, addfd->file);
> +	}
> +
> +out:
> +	addfd->ret = ret;
> +	complete(&addfd->completion);
> +}

My previous comment about SCM_RIGHTS still applies, right? That is, we
should do,

		sock = sock_from_file(fp[i], &err);
		if (sock) {
				sock_update_netprioidx(&sock->sk->sk_cgrp_data);
				sock_update_classid(&sock->sk->sk_cgrp_data);
		}

and perhaps lift that into a helper.

Tycho