From: Andy Lutomirski <luto@amacapital.net>
To: Colin Walters <walters@verbum.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Jamie Lokier <jamie@shareable.org>,
Will Drewry <wad@chromium.org>,
linux-kernel@vger.kernel.org, keescook@chromium.org,
john.johansen@canonical.com, serge.hallyn@canonical.com,
coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com,
djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org,
jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com,
penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu,
akpm@linux-foundation.org, khilman@ti.com,
borislav.petkov@amd.com, amwang@redhat.com, oleg@redhat.com,
ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de,
dhowells@redhat.com, daniel.lezcano@free.fr,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org, olofj@chromium.org,
mhalcrow@google.com, dlaor@redhat.com, corbet@lwn.net,
alan@lxorguk.ukuu.org.uk
Subject: Re: [PATCH v2 0/4] PR_SET_NO_NEW_PRIVS, unshare, and chroot
Date: Mon, 16 Jan 2012 13:57:47 -0800 [thread overview]
Message-ID: <CALCETrWCkX8DVRdyO5TEdeaobnW_+ic0OL7+8L6JeWwBcapNNw@mail.gmail.com> (raw)
In-Reply-To: <1326750422.3467.31.camel@lenny>
On Mon, Jan 16, 2012 at 1:47 PM, Colin Walters <walters@verbum.org> wrote:
> On Mon, 2012-01-16 at 13:25 -0800, Andy Lutomirski wrote:
>
>> The MS_NOSUID semantics are somewhat ridiculous for selinux,
>
> I don't see how they're ridiculous.
exec_sid is silently ignored. So runcon will not switch context but
will still appear to succeed.
>
>> and I'd
>> rather not make them match for no_new_privs.
>
> Note your patch for selinux does exactly the same thing in the NOSUID
> case and your NO_NEW_PRIVS flag. Right?
>
> - if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
> + if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
> + (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
> new_tsec->sid = old_tsec->sid;
>
See several lines up.
>
>> AppArmor completely
>> ignores MS_NOSUID,
>
> Ugh...well, I guess if it doesn't store any security data associated
> with files, only with file names, then there's nothing for it to do.
Nope. It looks it up by file name or path, I think.
> Like I said before though, I think SELinux is the only sane LSM.
I think the fact that there is a bprm_set_creds hook at all is insane,
but maybe that's just me. I think this is one of the things that
Windows does far better than POSIX. On Windows, CreateProcess (the
moral equivalent of execve) never gains privileges.
--Andy
prev parent reply other threads:[~2012-01-16 21:58 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 0:37 [PATCH v2 0/4] PR_SET_NO_NEW_PRIVS, unshare, and chroot Andy Lutomirski
2012-01-16 0:37 ` [PATCH v2 1/4] Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privs Andy Lutomirski
2012-01-16 17:33 ` Oleg Nesterov
2012-01-16 20:15 ` Andy Lutomirski
2012-01-16 0:37 ` [PATCH v2 2/4] Fix apparmor for PR_{GET,SET}_NO_NEW_PRIVS Andy Lutomirski
2012-01-16 0:37 ` [PATCH v2 3/4] Allow unprivileged CLONE_NEWUTS and CLONE_NEWIPC with no_new_privs Andy Lutomirski
2012-01-16 0:37 ` [PATCH 4/4] Allow unprivileged chroot when safe Andy Lutomirski
2012-01-16 0:45 ` Linus Torvalds
2012-01-16 1:08 ` Andy Lutomirski
2012-01-16 19:26 ` Colin Walters
2012-01-16 20:18 ` Andy Lutomirski
2012-01-17 10:14 ` Jamie Lokier
2012-01-16 20:06 ` Al Viro
2012-01-16 20:15 ` Andy Lutomirski
2012-01-16 20:26 ` Al Viro
2012-01-17 16:23 ` Oleg Nesterov
2012-01-17 16:31 ` Andy Lutomirski
2012-01-16 1:04 ` [PATCH v2 0/4] PR_SET_NO_NEW_PRIVS, unshare, and chroot Andy Lutomirski
2012-01-16 20:49 ` Colin Walters
2012-01-16 21:25 ` Andy Lutomirski
2012-01-16 21:47 ` Colin Walters
2012-01-16 21:57 ` Andy Lutomirski [this message]
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