From: Mimi Zohar <zohar@linux.ibm.com>
To: Christoph Hellwig <hch@infradead.org>,
Luis Chamberlain <mcgrof@kernel.org>
Cc: viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org,
rafael@kernel.org, ebiederm@xmission.com, jeyu@kernel.org,
jmorris@namei.org, keescook@chromium.org, paul@paul-moore.com,
stephen.smalley.work@gmail.com, eparis@parisplace.org,
nayna@linux.ibm.com, scott.branden@broadcom.com,
dan.carpenter@oracle.com, skhan@linuxfoundation.org,
geert@linux-m68k.org, tglx@linutronix.de, bauerman@linux.ibm.com,
dhowells@redhat.com, linux-integrity@vger.kernel.org,
linux-fsdevel@vger.kernel.org, kexec@lists.infradead.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] fs: reduce export usage of kerne_read*() calls
Date: Mon, 18 May 2020 08:37:42 -0400 [thread overview]
Message-ID: <1589805462.5111.107.camel@linux.ibm.com> (raw)
In-Reply-To: <20200518062255.GB15641@infradead.org>
Hi Christoph,
On Sun, 2020-05-17 at 23:22 -0700, Christoph Hellwig wrote:
> On Fri, May 15, 2020 at 09:29:33PM +0000, Luis Chamberlain wrote:
> > On Wed, May 13, 2020 at 11:17:36AM -0700, Christoph Hellwig wrote:
> > > Can you also move kernel_read_* out of fs.h? That header gets pulled
> > > in just about everywhere and doesn't really need function not related
> > > to the general fs interface.
> >
> > Sure, where should I dump these?
>
> Maybe a new linux/kernel_read_file.h? Bonus points for a small top
> of the file comment explaining the point of the interface, which I
> still don't get :)
Instead of rolling your own method of having the kernel read a file,
which requires call specific security hooks, this interface provides a
single generic set of pre and post security hooks. The
kernel_read_file_id enumeration permits the security hook to
differentiate between callers.
To comply with secure and trusted boot concepts, a file cannot be
accessible to the caller until after it has been measured and/or the
integrity (hash/signature) appraised.
In some cases, the file was previously read twice, first to measure
and/or appraise the file and then read again into a buffer for
use. This interface reads the file into a buffer once, calls the
generic post security hook, before providing the buffer to the caller.
(Note using firmware pre-allocated memory might be an issue.)
Partial reading firmware will result in needing to pre-read the entire
file, most likely on the security pre hook.
Mimi
next prev parent reply other threads:[~2020-05-18 12:38 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 15:21 [PATCH 0/3] fs: reduce export usage of kerne_read*() calls Luis Chamberlain
2020-05-13 15:21 ` [PATCH 1/3] fs: unexport kernel_read_file() Luis Chamberlain
2020-05-13 15:21 ` [PATCH 2/3] security: add symbol namespace for reading file data Luis Chamberlain
2020-05-13 15:40 ` Eric W. Biederman
2020-05-13 16:09 ` Greg KH
2020-05-13 16:16 ` Luis Chamberlain
2020-05-13 16:26 ` Greg KH
2020-05-13 18:07 ` Josh Triplett
2020-05-13 15:21 ` [PATCH 3/3] fs: move kernel_read*() calls to its own symbol namespace Luis Chamberlain
2020-05-13 16:08 ` Greg KH
2020-05-13 18:17 ` [PATCH 0/3] fs: reduce export usage of kerne_read*() calls Christoph Hellwig
2020-05-15 21:29 ` Luis Chamberlain
2020-05-18 6:22 ` Christoph Hellwig
2020-05-18 12:37 ` Mimi Zohar [this message]
2020-05-18 15:21 ` Kees Cook
2020-07-29 1:20 ` Luis Chamberlain
2020-05-22 22:24 ` Scott Branden
2020-05-22 23:04 ` Kees Cook
2020-05-22 23:25 ` Scott Branden
2020-05-24 2:52 ` Mimi Zohar
2020-06-05 18:15 ` Scott Branden
2020-06-05 18:37 ` Mimi Zohar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1589805462.5111.107.camel@linux.ibm.com \
--to=zohar@linux.ibm.com \
--cc=bauerman@linux.ibm.com \
--cc=dan.carpenter@oracle.com \
--cc=dhowells@redhat.com \
--cc=ebiederm@xmission.com \
--cc=eparis@parisplace.org \
--cc=geert@linux-m68k.org \
--cc=gregkh@linuxfoundation.org \
--cc=hch@infradead.org \
--cc=jeyu@kernel.org \
--cc=jmorris@namei.org \
--cc=keescook@chromium.org \
--cc=kexec@lists.infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mcgrof@kernel.org \
--cc=nayna@linux.ibm.com \
--cc=paul@paul-moore.com \
--cc=rafael@kernel.org \
--cc=scott.branden@broadcom.com \
--cc=selinux@vger.kernel.org \
--cc=skhan@linuxfoundation.org \
--cc=stephen.smalley.work@gmail.com \
--cc=tglx@linutronix.de \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).