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:	Mon, 2 Mar 2015 10:39:33 +0100 (CET)
From:	Jiri Kosina <jkosina@...e.cz>
To:	Yinghai Lu <yinghai@...nel.org>
cc:	Matt Fleming <matt.fleming@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...e.de>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	linux-kernel@...r.kernel.org, linux-efi@...r.kernel.org,
	linux-pci@...r.kernel.org
Subject: Re: [PATCH 1/8] x86, kaslr: get kaslr_enabled back correctly

On Sat, 28 Feb 2015, Yinghai Lu wrote:

> We should access variable with referrence instead of using physical
> address as value.
> 
> Cc: Matt Fleming <matt.fleming@...el.com>
> Cc: Borislav Petkov <bp@...e.de>
> Signed-off-by: Yinghai Lu <yinghai@...nel.org>

	Acked-by: Jiri Kosina <jkosina@...e.cz>


Thanks for fixing my brainfart. This is not fixing the problem with the 
later variable overwrite, but definitely needs to go in as well.

Thanks.

> ---
>  arch/x86/kernel/setup.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 98dc931..05d444f 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -429,7 +429,13 @@ static void __init reserve_initrd(void)
>  
>  static void __init parse_kaslr_setup(u64 pa_data, u32 data_len)
>  {
> -	kaslr_enabled = (bool)(pa_data + sizeof(struct setup_data));
> +	/* kaslr_setup_data is defined in aslr.c */
> +	unsigned char *data;
> +	unsigned long offset = sizeof(struct setup_data);
> +
> +	data = early_memremap(pa_data, offset + 1);
> +	kaslr_enabled = *(data + offset);
> +	early_memunmap(data, offset + 1);
>  }
>  
>  static void __init parse_setup_data(void)

-- 
Jiri Kosina
SUSE Labs
--
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/