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From: Arvind Sankar <niveditas98@gmail.com>
To: Rob Landley <rob@landley.net>
Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org,
	initramfs@vger.kernel.org
Subject: Re: [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk
Date: Sun, 12 May 2019 15:43:25 -0400
Message-ID: <20190512194322.GA71658@rani.riverdale.lan> (raw)
In-Reply-To: <dca50ee1-62d8-2256-6fdb-9a786e6cea5a@landley.net>

On Sun, May 12, 2019 at 05:05:48PM +0000, Rob Landley wrote:
> On 5/12/19 7:52 AM, Mimi Zohar wrote:
> > On Sun, 2019-05-12 at 11:17 +0200, Dominik Brodowski wrote:
> >> On Thu, May 09, 2019 at 01:24:17PM +0200, Roberto Sassu wrote:
> >>> This proposal consists in marshaling pathnames and xattrs in a file called
> >>> .xattr-list. They are unmarshaled by the CPIO parser after all files have
> >>> been extracted.
> >>
> >> Couldn't this parsing of the .xattr-list file and the setting of the xattrs
> >> be done equivalently by the initramfs' /init? Why is kernel involvement
> >> actually required here?
> > 
> > It's too late.  The /init itself should be signed and verified.
> 
> If the initramfs cpio.gz image was signed and verified by the extractor, how is
> the init in it _not_ verified?
> 
> Ro

Wouldn't the below work even before enforcing signatures on external
initramfs:
1. Create an embedded initramfs with an /init that does the xattr
parsing/setting. This will be verified as part of the kernel image
signature, so no new code required.
2. Add a config option/boot parameter to panic the kernel if an external
initramfs attempts to overwrite anything in the embedded initramfs. This
prevents overwriting the embedded /init even if the external initramfs
is unverified.

  reply index

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-09 11:24 Roberto Sassu
2019-05-09 11:24 ` [PATCH v2 1/3] fs: add ksys_lsetxattr() wrapper Roberto Sassu
2019-05-10 21:28   ` Jann Horn
2019-05-09 11:24 ` [PATCH v2 2/3] initramfs: set extended attributes Roberto Sassu
2019-05-09 11:24 ` [PATCH v2 3/3] initramfs: introduce do_readxattrs() Roberto Sassu
2019-05-10 21:33   ` Jann Horn
2019-05-13 13:03     ` Roberto Sassu
2019-05-09 18:34 ` [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk Rob Landley
2019-05-10  6:56   ` Roberto Sassu
2019-05-10 11:49     ` Mimi Zohar
2019-05-10 20:46       ` Rob Landley
2019-05-10 22:38         ` Mimi Zohar
2019-05-11 22:44 ` Andy Lutomirski
2019-05-12  4:04   ` Rob Landley
2019-05-12  4:12     ` Rob Landley
2019-05-12  9:17 ` Dominik Brodowski
2019-05-12 10:18   ` hpa
2019-05-12 15:31     ` Dominik Brodowski
2019-05-13  0:02       ` Mimi Zohar
2019-05-13  0:21         ` hpa
2019-05-13  0:23       ` hpa
2019-05-12 12:52   ` Mimi Zohar
2019-05-12 17:05     ` Rob Landley
2019-05-12 19:43       ` Arvind Sankar [this message]
2019-05-13  7:49         ` Roberto Sassu
2019-05-13  9:07           ` Rob Landley
2019-05-13 12:08             ` Mimi Zohar
2019-05-13 12:47             ` Roberto Sassu
2019-05-13 17:20               ` Arvind Sankar
2019-05-13 17:51                 ` Arvind Sankar
2019-05-13 17:52                 ` Arvind Sankar
2019-05-13 18:36                   ` Mimi Zohar
2019-05-13 18:47                     ` Arvind Sankar
2019-05-13 22:09                       ` Mimi Zohar
2019-05-14  6:06                         ` Rob Landley
2019-05-14 14:44                           ` Arvind Sankar
2019-05-14  6:06               ` Rob Landley
2019-05-14 11:52                 ` Roberto Sassu
2019-05-14 15:12                   ` Rob Landley
2019-05-14 15:27                   ` Arvind Sankar
2019-05-14 15:57                     ` Arvind Sankar
2019-05-14 17:44                       ` Roberto Sassu
2019-05-15  1:00                         ` Arvind Sankar
2019-05-14 15:19               ` Andy Lutomirski
2019-05-14 16:33                 ` Roberto Sassu
2019-05-14 16:58                   ` Greg KH
2019-05-14 17:20                     ` Roberto Sassu
2019-05-15  0:25                       ` Arvind Sankar
2019-05-14 19:18                 ` James Bottomley
2019-05-14 23:39                   ` Rob Landley
2019-05-14 23:54                     ` James Bottomley
2019-05-15  0:52                       ` Arvind Sankar
2019-05-15 11:19                         ` Roberto Sassu
2019-05-15 16:08                           ` Arvind Sankar
2019-05-15 17:06                             ` Roberto Sassu
2019-05-16  5:29                               ` Arvind Sankar
2019-05-16 11:42                                 ` Roberto Sassu
2019-05-16 13:31                                 ` Mimi Zohar

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