linux-kernel - Re: [PATCH 1/8] x86, kaslr: get kaslr

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

Date:	Sun, 1 Mar 2015 21:29:38 +0100
From:	Borislav Petkov <bp@...e.de>
To:	Yinghai Lu <yinghai@...nel.org>
Cc:	Ingo Molnar <mingo@...nel.org>, Jiri Kosina <jkosina@...e.cz>,
	Kees Cook <keescook@...omium.org>,
	Matt Fleming <matt.fleming@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>
Subject: Re: [PATCH 1/8] x86, kaslr: get kaslr_enabled back correctly

On Sun, Mar 01, 2015 at 12:24:08PM -0800, Yinghai Lu wrote:
> static allocation in misc.c can not be used to kernel/head_64.S stage safely.

Correct. One possibility that works is sticking it right below
LOAD_PHYSICAL_ADDR:

+static void add_kaslr_setup_data(struct boot_params *params,
+				 u8 *output, __u8 enabled)
 {
+	/*
+	 * Stick it right under LOAD_PHYSICAL_ADDR
+	 */
+	ksd = (struct setup_data *)(output - 2 * sizeof(struct setup_data));

output is LOAD_PHYSICAL_ADDR AFAICT and is the minimum kASLR considers
so right below it should work:

https://lkml.kernel.org/r/20150228105049.GA11038@pd.tnic

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/