From: Tyler Hicks <tyhicks@linux.microsoft.com>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>,
"Kenneth R . Crudup" <kenny@panix.com>,
Mimi Zohar <zohar@linux.ibm.com>
Cc: "Peter Huewe" <peterhuewe@gmx.de>,
"Jarkko Sakkinen" <jarkko@kernel.org>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-efi@vger.kernel.org, "Thiébaud Weksteen" <tweek@google.com>,
"Ard Biesheuvel" <ardb@kernel.org>
Subject: Re: [PATCH] tpm: efi: Don't create binary_bios_measurements file for an empty log
Date: Wed, 28 Oct 2020 12:39:58 -0500 [thread overview]
Message-ID: <20201028173958.GA4624@sequoia> (raw)
In-Reply-To: <20201028163002.GA5150@sequoia>
On 2020-10-28 11:30:11, Tyler Hicks wrote:
> So, we need help from Kai, Kenneth, or Mimi to verify my assumption that
> their firmware is providing an empty main event log and a populated
> final event log.
Hi Kai, Kenneth, and Mimi - could one or two of you please follow these
steps:
1) Apply the proposed patch in the grandparent of this email so that
your kernel doesn't crash
2) Revert commit 7f3d176f5f7e ("tpm: Require that all digests are
present in TCG_PCR_EVENT2 structures") so that
__calc_tpm2_event_size() goes back to being less picky and may treat
a final log event as a valid event log header
3) Add some debugging warnings in efi_tpm_eventlog_init() to check for
an empty main event log and a populated final event log, as shown
below
4) Boot the resulting kernel build, look for the warnings, and report
back
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
index c1955d320fec..c4d2dbd5ed42 100644
--- a/drivers/firmware/efi/tpm.c
+++ b/drivers/firmware/efi/tpm.c
@@ -78,6 +78,9 @@ int __init efi_tpm_eventlog_init(void)
goto out;
}
+ WARN(!log_tbl->size && final_tbl->nr_events,
+ "nr_events = %llu\n", final_tbl->nr_events);
+
tbl_size = 0;
if (final_tbl->nr_events != 0) {
void *events = (void *)efi.tpm_final_log
@@ -95,6 +98,8 @@ int __init efi_tpm_eventlog_init(void)
goto out_calc;
}
+ WARN(!log_tbl->size && tbl_size, "tbl_size = %d\n", tbl_size);
+
memblock_reserve((unsigned long)final_tbl,
tbl_size + sizeof(*final_tbl));
efi_tpm_final_log_size = tbl_size;
For your convenience, I've created a branch with these changes on top of
v5.9:
https://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/linux.git/log/?h=tpm/bin-bios-measurements-debug
Thank you!
Tyler
next prev parent reply other threads:[~2020-10-28 22:27 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-28 12:31 [Regression] "tpm: Require that all digests are present in TCG_PCR_EVENT2 structures" causes null pointer dereference Kai-Heng Feng
2020-09-28 14:06 ` Jarkko Sakkinen
2020-09-28 14:16 ` Kai-Heng Feng
[not found] ` <20200928155215.GA92669@linux.intel.com>
2020-09-28 16:15 ` Ard Biesheuvel
2020-09-28 16:26 ` Ard Biesheuvel
2020-09-28 17:12 ` Jarkko Sakkinen
2020-09-28 18:05 ` Kenneth R. Crudup
2020-09-29 17:52 ` Mimi Zohar
2020-09-30 2:20 ` Jarkko Sakkinen
2020-10-08 9:09 ` Kai-Heng Feng
2020-10-09 16:06 ` Jarkko Sakkinen
2020-10-13 14:31 ` Tyler Hicks
2020-10-13 14:33 ` Jarkko Sakkinen
2020-10-20 21:07 ` Mimi Zohar
2020-10-21 5:48 ` Tyler Hicks
[not found] ` <2A43F8DD-7E07-4435-9666-63B8105ABF82@canonical.com>
2020-10-27 5:08 ` Tyler Hicks
2020-10-28 15:41 ` [PATCH] tpm: efi: Don't create binary_bios_measurements file for an empty log Tyler Hicks
2020-10-28 16:30 ` Tyler Hicks
2020-10-28 17:39 ` Tyler Hicks [this message]
2020-10-30 6:41 ` Kai-Heng Feng
2020-11-04 2:12 ` Kenneth R. Crudup
2020-10-30 4:46 ` Jarkko Sakkinen
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=20201028173958.GA4624@sequoia \
--to=tyhicks@linux.microsoft.com \
--cc=ardb@kernel.org \
--cc=jarkko@kernel.org \
--cc=jgg@ziepe.ca \
--cc=kai.heng.feng@canonical.com \
--cc=kenny@panix.com \
--cc=linux-efi@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterhuewe@gmx.de \
--cc=tweek@google.com \
--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).