From: Vasily Averin <vvs@virtuozzo.com>
To: linux-integrity@vger.kernel.org
Cc: Peter Huewe <peterhuewe@gmx.de>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Jason Gunthorpe <jgg@ziepe.ca>
Subject: [PATCH v2 0/2] tpm: seq_file .next functions should increase position index
Date: Thu, 30 Jan 2020 13:23:10 +0300 [thread overview]
Message-ID: <2407362b-ce82-f585-7a00-e1e9b3ea6e60@virtuozzo.com> (raw)
In-Reply-To: <e72b6fda6c4ff0d54af37d064d66b883d7ea48e7.camel@linux.intel.com>
v2: improved patch description
In Aug 2018 NeilBrown noticed
commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface")
"Some ->next functions do not increment *pos when they return NULL...
Note that such ->next functions are buggy and should be fixed.
A simple demonstration is
dd if=/proc/swaps bs=1000 skip=1
Choose any block size larger than the size of /proc/swaps. This will
always show the whole last line of /proc/swaps"
Described problem is still actual. If you make lseek into middle of last output line
following read will output end of last line and whole last line once again.
$ dd if=/proc/swaps bs=1 # usual output
Filename Type Size Used Priority
/dev/dm-0 partition 4194812 97536 -2
104+0 records in
104+0 records out
104 bytes copied
$ dd if=/proc/swaps bs=40 skip=1 # last line was generated twice
dd: /proc/swaps: cannot skip to specified offset
v/dm-0 partition 4194812 97536 -2
/dev/dm-0 partition 4194812 97536 -2
3+1 records in
3+1 records out
131 bytes copied
There are lot of other affected files, I've found 30+ including
/proc/net/ip_tables_matches and /proc/sysvipc/*
This patch-set fixes files related to tpm driver:
/sys/kernel/security/tpm0/ascii_bios_measurements
/sys/kernel/security/tpm0/binary_bios_measurements
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Vasily Averin (2):
tpm: tpm1_bios_measurements_next should increase position index
tpm: tpm2_bios_measurements_next should increase position index
drivers/char/tpm/eventlog/tpm1.c | 2 +-
drivers/char/tpm/eventlog/tpm2.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--
1.8.3.1
next prev parent reply other threads:[~2020-01-30 10:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-23 7:48 [PATCH 1/2] tpm1_bios_measurements_next should increase position index Vasily Averin
2020-01-29 13:23 ` Jarkko Sakkinen
2020-01-29 13:25 ` Jarkko Sakkinen
2020-01-30 10:23 ` Vasily Averin [this message]
2020-01-30 10:23 ` [PATCH v2 1/2] tpm: " Vasily Averin
2020-01-30 10:23 ` [PATCH v2 2/2] tpm: tpm2_bios_measurements_next " Vasily Averin
2020-02-01 17:03 ` Jarkko Sakkinen
2020-02-03 5:14 ` Vasily Averin
2020-02-05 22:03 ` Jarkko Sakkinen
2020-02-25 6:26 ` [PATCH v3 1/2] tpm: tpm1_bios_measurements_next " Vasily Averin
2020-02-25 10:27 ` Jarkko Sakkinen
2020-02-25 10:29 ` Jarkko Sakkinen
2020-02-25 6:26 ` [PATCH v3 2/2] tpm: tpm2_bios_measurements_next " Vasily Averin
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=2407362b-ce82-f585-7a00-e1e9b3ea6e60@virtuozzo.com \
--to=vvs@virtuozzo.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jgg@ziepe.ca \
--cc=linux-integrity@vger.kernel.org \
--cc=peterhuewe@gmx.de \
/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).