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From: Pavel Machek <pavel@ucw.cz>
To: Timur Tabi <timur@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	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,
	keescook@chromium.org, 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 21:48:35 +0100	[thread overview]
Message-ID: <20210204204835.GA7529@amd> (raw)
In-Reply-To: <20210202201846.716915-1-timur@kernel.org>

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On Tue 2021-02-02 14:18:46, Timur Tabi wrote:
> If the make-printk-non-secret command-line parameter is set, then
> printk("%p") will print addresses as unhashed.  This is useful for
> debugging purposes.
> 
> A large warning message is displayed if this option is enabled,
> because unhashed addresses, while useful for debugging, exposes
> kernel addresses which can be a security risk.

Yes please. I needed to see pointers for debugging, and seeing hashed
pointers is nasty. Having to patch C code to be able to develop... is
bad.

> +	pr_warn("** Kernel memory addresses are exposed, which may       **\n");
> +	pr_warn("** compromise security on your system.                  **\n");

This is lies, right? And way too verbose.

									Pavel
-- 
http://www.livejournal.com/~pavelmachek

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  parent reply	other threads:[~2021-02-04 20:48 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 [this message]
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
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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