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Date: Mon, 9 Nov 2015 14:11:35 -0500
Message-ID: <CAGagf4d4A8ZN2hVDDUFge78D_AZKFwkh6ZCV9faEZe=DO_fwKQ@mail.gmail.com>
From: Theodore Tso <tytso@google.com>
Content-Type: multipart/alternative; boundary=001a114295d0adf4e20524205c96
Subject: Re: [kernel-hardening] Re: Proposal for kernel self protection features
To: Jason Cooper <kernel-hardening@lakedaemon.net>
Cc: kernel-hardening@lists.openwall.com, Emese Revfy <re.emese@gmail.com>, Kees Cook <keescook@chromium.org>, PaX Team <pageexec@freemail.hu>, Brad Spengler <spender@grsecurity.net>, Greg KH <gregkh@linuxfoundation.org>, Josh Triplett <josh@joshtriplett.org>
List-ID: <kernel-hardening.lists.openwall.com>

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On Mon, Nov 9, 2015 at 2:02 PM, Jason Cooper <
kernel-hardening@lakedaemon.net> wrote:

> /var/lib/misc/random-seed has served that role for years, I'm only
> advocating loading it earlier in the boot process.  It's *much* harder
> to guess the state of random-seed than the dtb or mac address(es)...
>

If the bootloader is willing to reach into the file system, which means (a)
having a minimal file system layer, like Grub does, and (b) can find the
block device where the file is found, that's a perfectly *fine*
implementation.    I'm not sure mobile handset vendors will be all that
psyched into either using or replicating all of Grub's functionality so it
could do that, though....

-- Ted

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<div dir=3D"ltr"><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">=
On Mon, Nov 9, 2015 at 2:02 PM, Jason Cooper <span dir=3D"ltr">&lt;<a href=
=3D"mailto:kernel-hardening@lakedaemon.net" target=3D"_blank" class=3D"crem=
ed">kernel-hardening@lakedaemon.net</a>&gt;</span> wrote:<br><blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;p=
adding-left:1ex"><div id=3D":346" class=3D"a3s" style=3D"overflow:hidden">/=
var/lib/misc/random-seed has served that role for years, I&#39;m only<br>
advocating loading it earlier in the boot process.=C2=A0 It&#39;s *much* ha=
rder<br>
to guess the state of random-seed than the dtb or mac address(es)...<br></d=
iv></blockquote></div><br>If the bootloader is willing to reach into the fi=
le system, which means (a) having a minimal file system layer, like Grub do=
es, and (b) can find the block device where the file is found, that&#39;s a=
 perfectly *fine* implementation. =C2=A0 =C2=A0I&#39;m not sure mobile hand=
set vendors will be all that psyched into either using or replicating all o=
f Grub&#39;s functionality so it could do that, though....</div><div class=
=3D"gmail_extra"><br></div><div class=3D"gmail_extra">-- Ted</div><div clas=
s=3D"gmail_extra"><br></div></div>

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