From: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
To: Peter Jones <pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 5/5] efi: Make efivarfs entries immutable by default.
Date: Wed, 3 Feb 2016 14:13:54 +0000 [thread overview]
Message-ID: <20160203141354.GH2597@codeblueprint.co.uk> (raw)
In-Reply-To: <1454504567-2826-5-git-send-email-pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
On Wed, 03 Feb, at 08:02:47AM, Peter Jones wrote:
> "rm -rf" is bricking some peoples' laptops because of variables being
> used to store non-reinitializable firmware driver data that's required
> to POST the hardware.
>
> These are 100% bugs, and they need to be fixed, but in the mean time it
> shouldn't be easy to *accidentally* brick machines.
>
> We have to have delete working, and picking which variables do and don't
> work for deletion is quite intractable, so instead make everything
> immutable by default (except for a whitelist), and make tools that
> aren't quite so broad-spectrum unset the immutable flag.
>
> v2: adds Timeout to our whitelist.
>
> Signed-off-by: Peter Jones <pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
> drivers/firmware/efi/vars.c | 83 +++++++++++++++++++++++++++++++++------------
> fs/efivarfs/file.c | 69 +++++++++++++++++++++++++++++++++++++
> fs/efivarfs/inode.c | 32 +++++++++++------
> fs/efivarfs/internal.h | 3 +-
> fs/efivarfs/super.c | 9 +++--
> include/linux/efi.h | 2 ++
> 6 files changed, 163 insertions(+), 35 deletions(-)
I see no mention of the benefit of using the immutable flag versus
making all protected files read-only.
Is it not possible to just make everything that needs protecting 444?
That way users can use standard tools if they really, really want to
delete/write to a variable. It has the added benefit of protecting
users from trashing variables that are important for POST too (as
opposed to deleting them altogether).
next prev parent reply other threads:[~2016-02-03 14:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 13:02 [PATCH 1/5] Add ucs2 -> utf8 helper functions Peter Jones
[not found] ` <1454504567-2826-1-git-send-email-pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-02-03 13:02 ` [PATCH 2/5] efi: use ucs2_as_utf8 in efivarfs instead of open coding a bad version Peter Jones
[not found] ` <1454504567-2826-2-git-send-email-pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-02-03 16:42 ` Matt Fleming
[not found] ` <20160203164245.GA15385-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-02-03 16:55 ` [PATCH] efi: use ucs2_as_utf8 in efivarfs instead of open coding a bad version (v2) Peter Jones
2016-02-03 13:02 ` [PATCH 3/5] efi: do variable name validation tests in utf8 Peter Jones
2016-02-03 13:02 ` [PATCH 4/5] efi: make our variable validation list include the guid Peter Jones
2016-02-03 13:02 ` [PATCH 5/5] efi: Make efivarfs entries immutable by default Peter Jones
[not found] ` <1454504567-2826-5-git-send-email-pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-02-03 14:13 ` Matt Fleming [this message]
[not found] ` <20160203141354.GH2597-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-02-03 14:20 ` Steve McIntyre
[not found] ` <20160203141959.GA3319-nt0JYOx6u4DQT0dZR+AlfA@public.gmane.org>
2016-02-03 14:50 ` Leif Lindholm
[not found] ` <20160203145005.GH10351-t77nlHhSwNqAroYi2ySoxKxOck334EZe@public.gmane.org>
2016-02-03 14:56 ` Matt Fleming
[not found] ` <20160203145621.GI2597-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-02-03 15:00 ` Steve McIntyre
-- strict thread matches above, loose matches on Subject: below --
2016-02-12 11:27 [GIT PULL 0/5] EFI urgent fixes Matt Fleming
2016-02-12 11:27 ` [PATCH 5/5] efi: Make efivarfs entries immutable by default Matt Fleming
[not found] ` <1455276432-9931-6-git-send-email-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-02-15 10:50 ` Matt Fleming
2016-02-02 22:33 Preventing "rm -rf /sys/firmware/efi/efivars/" from damage Peter Jones
[not found] ` <1454452386-27709-1-git-send-email-pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-02-02 22:33 ` [PATCH 5/5] efi: Make efivarfs entries immutable by default Peter Jones
[not found] ` <1454452386-27709-6-git-send-email-pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-02-03 13:16 ` Matt Fleming
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