linux-kernel - [PATCH 0/2] printk.kmsg: Ratelimit it by default

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1465899128-4522-1-git-send-email-bp@alien8.de>
Date:	Tue, 14 Jun 2016 12:12:06 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Steven Rostedt <rostedt@...dmis.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 0/2] printk.kmsg: Ratelimit it by default

From: Borislav Petkov <bp@...e.de>

Ok, so how about these two?

Rostedt is busy so I took Linus' old patch and Steven's last v2 and
split and extended them with the comments people had on the last thread:

https://lkml.kernel.org/r/20160425145606.598329f2@gandalf.local.home

I hope, at least.

So it is ratelimiting by default, with "on" and "off" cmdline options. I
called the option somewhat a bit shorter too: "printk.kmsg"

The current use cases of this and of which I'm aware are:

* debug the kernel and thus shut up all interfering input from
userspace, i.e. boot with "printk.kmsg=off"

* debug userspace (and by that I mean systemd) by booting with
"printk.kmsg=on" so that the ratelimiting is disabled and the kernel log
gets all the spew.

Thoughts?

Thanks.

Borislav Petkov (2):
  ratelimit: Extend to print suppressed messages on release
  printk: Add kernel parameter to control writes to /dev/kmsg

 Documentation/kernel-parameters.txt |  6 ++++
 include/linux/ratelimit.h           | 36 +++++++++++++++++++----
 kernel/printk/printk.c              | 57 +++++++++++++++++++++++++++++++------
 lib/ratelimit.c                     |  6 ++--
 4 files changed, 90 insertions(+), 15 deletions(-)

-- 
2.7.3