[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CALCETrWzfgNvOHmKy5205A2qLJLYCZ+5RZOQR9vzQ1ubpo0vNA@mail.gmail.com>
Date: Thu, 25 Aug 2016 04:12:02 -0700
From: Andy Lutomirski <luto@...capital.net>
To: Mickaël Salaün <mic@...ikod.net>,
"Eric W. Biederman" <ebiederm@...ssion.com>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, Alexei Starovoitov <ast@...nel.org>,
Arnd Bergmann <arnd@...db.de>, Casey Schaufler <casey@...aufler-ca.com>,
Daniel Borkmann <daniel@...earbox.net>, Daniel Mack <daniel@...que.org>,
David Drysdale <drysdale@...gle.com>, "David S . Miller" <davem@...emloft.net>,
Elena Reshetova <elena.reshetova@...el.com>, James Morris <james.l.morris@...cle.com>,
Kees Cook <keescook@...omium.org>, Paul Moore <pmoore@...hat.com>,
Sargun Dhillon <sargun@...gun.me>, "Serge E . Hallyn" <serge@...lyn.com>, Will Drewry <wad@...omium.org>,
"kernel-hardening@...ts.openwall.com" <kernel-hardening@...ts.openwall.com>, Linux API <linux-api@...r.kernel.org>,
LSM List <linux-security-module@...r.kernel.org>,
Network Development <netdev@...r.kernel.org>
Subject: Re: [RFC v2 08/10] landlock: Handle file system comparisons
On Thu, Aug 25, 2016 at 3:32 AM, Mickaël Salaün <mic@...ikod.net> wrote:
> Add eBPF functions to compare file system access with a Landlock file
> system handle:
> * bpf_landlock_cmp_fs_prop_with_struct_file(prop, map, map_op, file)
> This function allows to compare the dentry, inode, device or mount
> point of the currently accessed file, with a reference handle.
> * bpf_landlock_cmp_fs_beneath_with_struct_file(opt, map, map_op, file)
> This function allows an eBPF program to check if the current accessed
> file is the same or in the hierarchy of a reference handle.
>
> The goal of file system handle is to abstract kernel objects such as a
> struct file or a struct inode. Userland can create this kind of handle
> thanks to the BPF_MAP_UPDATE_ELEM command. The element is a struct
> landlock_handle containing the handle type (e.g.
> BPF_MAP_HANDLE_TYPE_LANDLOCK_FS_FD) and a file descriptor. This could
> also be any descriptions able to match a struct file or a struct inode
> (e.g. path or glob string).
This needs Eric's opinion.
Also, where do all the struct file *'s get stashed? Are they
preserved in the arraymap? What prevents reference cycles or absurdly
large numbers of struct files getting pinned?
--Andy
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
