From: Kees Cook <keescook@chromium.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: Timur Tabi <timur@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
willy@infradead.org, akpm@linux-foundation.org,
torvalds@linux-foundation.org, roman.fietze@magna.com,
john.ogness@linutronix.de, akinobu.mita@gmail.com
Subject: Re: [PATCH] lib/vsprintf: make-printk-non-secret printks all addresses as unhashed
Date: Thu, 4 Feb 2021 14:17:13 -0800 [thread overview]
Message-ID: <202102041415.D9093ED6@keescook> (raw)
In-Reply-To: <20210204221143.GB13103@amd>
On Thu, Feb 04, 2021 at 11:11:43PM +0100, Pavel Machek wrote:
> On Thu 2021-02-04 15:59:21, Timur Tabi wrote:
> > On 2/4/21 3:49 PM, Pavel Machek wrote:
> > >This machine is insecure. Yet I don't see ascii-art *** all around..
> > >
> > >"Kernel memory addresses are exposed, which is bad for security."
> >
> > I'll use whatever wording everyone can agree on, but I really don't see much
> > difference between "which may compromise security on your system" and "which
> > is bad for security". "may compromise" doesn't see any more alarmist than
> > "bad". Frankly, "bad" is a very generic term.
>
> Well, I agree that "bad" is vague.... but original wording is simply
> untrue, as printing addresses decreases robustness but can't introduce
> security problem on its own.
>
> Being alarmist is not my complaint; being untrue is.
It's just semantics. Printing addresses DOES weaken the security of a
system, especially when we know attackers have and do use stuff from dmesg
to tune their attacks. How about "reduces the security of your system"?
--
Kees Cook
next prev parent reply other threads:[~2021-02-04 22:17 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 20:18 Timur Tabi
2021-02-02 21:52 ` Kees Cook
2021-02-02 22:19 ` Timur Tabi
2021-02-02 22:34 ` Steven Rostedt
2021-02-02 22:51 ` Linus Torvalds
2021-02-03 18:53 ` Kees Cook
2021-02-04 20:48 ` Pavel Machek
2021-02-04 20:54 ` Steven Rostedt
2021-02-04 21:49 ` Pavel Machek
2021-02-04 21:59 ` Timur Tabi
2021-02-04 22:06 ` Steven Rostedt
2021-02-04 22:11 ` Pavel Machek
2021-02-04 22:17 ` Kees Cook [this message]
2021-02-04 22:20 ` Timur Tabi
2021-02-04 22:51 ` Pavel Machek
2021-02-04 22:57 ` Pavel Machek
2021-02-04 22:05 ` Steven Rostedt
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