linux-kernel - Re: [PATCH 16/24] init: add an init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200721171036.GX2786714@ZenIV.linux.org.uk>
Date:   Tue, 21 Jul 2020 18:10:36 +0100
From:   Al Viro <viro@...iv.linux.org.uk>
To:     Christoph Hellwig <hch@....de>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org, linux-raid@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-api@...r.kernel.org
Subject: Re: [PATCH 16/24] init: add an init_chroot helper

On Tue, Jul 21, 2020 at 06:28:10PM +0200, Christoph Hellwig wrote:

> +int __init init_chroot(const char *filename)
> +{
> +	struct path path;
> +	int error;
> +
> +	error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
> +	if (error)
> +		return error;
> +	error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);

Matter of taste, but if we do that, I wonder if we would be better off with
	error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
	if (!error && !ns_capable(current_user_ns(), CAP_SYS_CHROOT))
		error = -EPERM;
	if (!error)
		error = security_path_chroot(&path);
	if (!error)
		set_fs_root(current->fs, &path);
	path_put(&path);
	return error;