From: Luis Chamberlain <mcgrof@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
Christoph Hellwig <hch@infradead.org>,
viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org,
rafael@kernel.org, ebiederm@xmission.com, jeyu@kernel.org,
jmorris@namei.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: Wed, 29 Jul 2020 01:20:39 +0000 [thread overview]
Message-ID: <20200729012039.GN4332@42.do-not-panic.com> (raw)
In-Reply-To: <202005180820.46CEF3C2@keescook>
On Mon, May 18, 2020 at 08:21:08AM -0700, Kees Cook wrote:
> On Mon, May 18, 2020 at 08:37:42AM -0400, Mimi Zohar wrote:
> > 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.
>
> Well described! :)
Since you're moving all this stuff, it woudl be good if you can add this
as part of new kdoc as well.
Luis
next prev parent reply other threads:[~2020-07-29 1:20 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
2020-05-18 15:21 ` Kees Cook
2020-07-29 1:20 ` Luis Chamberlain [this message]
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=20200729012039.GN4332@42.do-not-panic.com \
--to=mcgrof@kernel.org \
--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=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 \
--cc=zohar@linux.ibm.com \
/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).