From: Hans de Goede <hdegoede@redhat.com>
To: "Luis R. Rodriguez" <mcgrof@kernel.org>,
Mimi Zohar <zohar@linux.vnet.ibm.com>,
Kees Cook <keescook@chromium.org>
Cc: Darren Hart <dvhart@infradead.org>,
Andy Shevchenko <andy@infradead.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H . Peter Anvin" <hpa@zytor.com>,
platform-driver-x86@vger.kernel.org,
linux-kernel@vger.kernel.org, Peter Jones <pjones@redhat.com>,
Dave Olsthoorn <dave@bewaar.me>,
Will Deacon <will.deacon@arm.com>,
Andy Lutomirski <luto@kernel.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
David Howells <dhowells@redhat.com>,
Josh Triplett <josh@joshtriplett.org>,
dmitry.torokhov@gmail.com, mfuzzey@parkeon.com,
Kalle Valo <kvalo@codeaurora.org>,
Arend Van Spriel <arend.vanspriel@broadcom.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
nbroeking@me.com, bjorn.andersson@linaro.org,
Torsten Duwe <duwe@suse.de>,
x86@kernel.org, linux-efi@vger.kernel.org
Subject: Re: [PATCH v3 2/5] efi: Add embedded peripheral firmware support
Date: Tue, 24 Apr 2018 17:09:52 +0200 [thread overview]
Message-ID: <71e6a45a-398d-b7a4-dab0-8b9936683226@redhat.com> (raw)
In-Reply-To: <20180423211143.GZ14440@wotan.suse.de>
Hi,
On 23-04-18 23:11, Luis R. Rodriguez wrote:
> Hans, please see use of READING_FIRMWARE_PREALLOC_BUFFER, we'll need a new ID
> and security for this type of request so IMA can reject it if the policy is
> configured for it.
Hmm, interesting, actually it seems like the whole existence
of READING_FIRMWARE_PREALLOC_BUFFER is a mistake, the IMA
framework really does not care if we are loading the firmware
into memory allocated by the firmware-loader code, or into
memory allocated by the device-driver requesting the firmware.
As such the current IMA code (from v4.17-rc2) actually does
not handle READING_FIRMWARE_PREALLOC_BUFFER at all, here
are bits of code from: security/integrity/ima/ima_main.c:
static int read_idmap[READING_MAX_ID] = {
[READING_FIRMWARE] = FIRMWARE_CHECK,
[READING_MODULE] = MODULE_CHECK,
[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
[READING_POLICY] = POLICY_CHECK
};
int ima_post_read_file(struct file *file, void *buf, loff_t size,
...
if (!file && read_id == READING_FIRMWARE) {
if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
(ima_appraise & IMA_APPRAISE_ENFORCE))
return -EACCES; /* INTEGRITY_UNKNOWN */
return 0;
}
Which show that the IMA code is not handling
READING_FIRMWARE_PREALLOC_BUFFER as it should (I believe it
should handle it the same as READING_FIRMWARE).
Now we could fix that, but the only user of
READING_FIRMWARE_PREALLOC_BUFFER is the code which originally
introduced it:
https://patchwork.kernel.org/patch/9162011/
So I believe it might be better to instead replace it
with just READING_FIRMWARE and find another way to tell
kernel_read_file() that there is a pre-allocated buffer,
perhaps the easiest way there is that *buf must be
NULL when the caller wants kernel_read_file() to
vmalloc the mem. This would of course require auditing
all callers that the buf which the pass in is initialized
to NULL.
Either way adding a third READING_FIRMWARE_FOO to the
kernel_read_file_id enum seems like a bad idea, from
the IMA pov firmware is firmware.
What this whole exercise has shown me though is that
I need to call security_kernel_post_read_file() when
loading EFI embedded firmware. I will add a call to
security_kernel_post_read_file() for v4 of the patch-set.
> Please Cc Kees in future patches.
Will do.
Regards,
Hans
next prev parent reply other threads:[~2018-04-24 15:09 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-08 17:40 [PATCH v3 0/5] efi/firmware/platform-x86: Add EFI embedded fw support Hans de Goede
2018-04-08 17:40 ` [PATCH v3 1/5] efi: Export boot-services code and data as debugfs-blobs Hans de Goede
2018-04-16 8:23 ` Ard Biesheuvel
2018-04-24 13:11 ` Hans de Goede
2018-04-23 11:55 ` Greg Kroah-Hartman
2018-04-08 17:40 ` [PATCH v3 2/5] efi: Add embedded peripheral firmware support Hans de Goede
2018-04-16 8:28 ` Ard Biesheuvel
2018-04-24 13:17 ` Hans de Goede
2018-04-17 0:17 ` Luis R. Rodriguez
2018-04-17 8:58 ` Hans de Goede
2018-04-17 9:19 ` Hans de Goede
2018-04-23 21:11 ` Luis R. Rodriguez
2018-04-24 15:09 ` Hans de Goede [this message]
2018-04-24 16:07 ` Mimi Zohar
2018-04-24 18:33 ` Hans de Goede
2018-04-24 23:42 ` Luis R. Rodriguez
2018-04-25 5:00 ` Mimi Zohar
2018-04-25 17:55 ` Luis R. Rodriguez
2018-05-04 0:21 ` Luis R. Rodriguez
2018-05-04 15:26 ` Martijn Coenen
2018-05-04 19:44 ` Martijn Coenen
2018-05-08 15:38 ` Luis R. Rodriguez
2018-05-08 16:10 ` Luis R. Rodriguez
2018-06-07 16:49 ` Bjorn Andersson
2018-06-07 18:22 ` Luis R. Rodriguez
2018-06-01 19:23 ` Luis R. Rodriguez
2018-06-06 20:32 ` Do Qualcomm drivers use DMA buffers for request_firmware_into_buf()? Luis R. Rodriguez
2018-06-07 16:18 ` Bjorn Andersson
[not found] ` <CAKv+Gu8+Fq7BD4XD-YCyXzZh0mg6Z2k-0styj0cw6_uZfaqy4Q@mail.gmail.com>
[not found] ` <20180607163308.GA18834@kroah.com>
2018-06-08 6:41 ` Vlastimil Babka
2018-06-07 16:33 ` [PATCH v3 2/5] efi: Add embedded peripheral firmware support Bjorn Andersson
2018-04-08 17:40 ` [PATCH v3 3/5] platform/x86: Rename silead_dmi to touchscreen_dmi Hans de Goede
2018-04-09 8:07 ` Andy Shevchenko
2018-04-20 0:20 ` Darren Hart
2018-04-08 17:40 ` [PATCH v3 4/5] platform/x86: touchscreen_dmi: Add EFI embedded firmware info support Hans de Goede
2018-04-08 17:40 ` [PATCH v3 5/5] platform/x86: touchscreen_dmi: Add info for the Chuwi Vi8 Plus tablet Hans de Goede
2018-04-09 8:10 ` Andy Shevchenko
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=71e6a45a-398d-b7a4-dab0-8b9936683226@redhat.com \
--to=hdegoede@redhat.com \
--cc=andy@infradead.org \
--cc=ard.biesheuvel@linaro.org \
--cc=arend.vanspriel@broadcom.com \
--cc=bjorn.andersson@linaro.org \
--cc=dave@bewaar.me \
--cc=dhowells@redhat.com \
--cc=dmitry.torokhov@gmail.com \
--cc=duwe@suse.de \
--cc=dvhart@infradead.org \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=josh@joshtriplett.org \
--cc=keescook@chromium.org \
--cc=kvalo@codeaurora.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=matt@codeblueprint.co.uk \
--cc=mcgrof@kernel.org \
--cc=mfuzzey@parkeon.com \
--cc=mingo@redhat.com \
--cc=nbroeking@me.com \
--cc=pjones@redhat.com \
--cc=platform-driver-x86@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=will.deacon@arm.com \
--cc=x86@kernel.org \
--cc=zohar@linux.vnet.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).