Linux-Integrity Archive on lore.kernel.org
 help / color / Atom feed
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
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


  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23  7:48 [PATCH 1/2] tpm1_bios_measurements_next " 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

Linux-Integrity Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-integrity/0 linux-integrity/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-integrity linux-integrity/ https://lore.kernel.org/linux-integrity \
		linux-integrity@vger.kernel.org
	public-inbox-index linux-integrity

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-integrity


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git