linux-kernel - Re: [PATCH] THE LINUX/I386 BOOT PROTOCOL

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]

Message-ID: <9e0cf0bf0608271259p688b8838rc181d3b03cf09996@mail.gmail.com>
Date:	Sun, 27 Aug 2006 22:59:53 +0300
From:	"Alon Bar-Lev" <alon.barlev@...il.com>
To:	"Andi Kleen" <ak@...e.de>
Cc:	"H. Peter Anvin" <hpa@...or.com>, "Andrew Morton" <akpm@...l.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] THE LINUX/I386 BOOT PROTOCOL - Breaking the 256 limit (ping)

On 8/27/06, Andi Kleen <ak@...e.de> wrote:
> Just increasing that constant caused various lilo setups to not boot
> anymore. I don't know who is actually to blame, just wanting to
> point out that this "obvious" patch isn't actually that obvious.
>
> -Andi
>

Hello,

lilo has its own COMMAND_LINE_SIZE constant.  It is not depended on
the kernel one.

lilo-22.7 lilo.h:
#define COMMAND_LINE_SIZE        256     /* CL_LENGTH */

lilo-22.7.2 lilo.h:
#define COMMAND_LINE_SIZE       512     /* CL_LENGTH */

So at worse case scenario it passes 256 bytes into the kernel
truncated with null terminated. Best case scenario it passes 512
bytes. Anyway... As long as you don't modify lilo, the kernel can
expect what-ever command-line length it wishes and truncate it to
match its own COMMAND_LINE_SIZE.

Please notice that we modify the kernel so it can accept long command
lines at boot protocol >= 2.02, but we don't modify  lilo behavior. So
lilo user will not be able to use the long command line size, until
lilo is modified to support it.

There is also a problem with grub, I've written a patch for it:
https://savannah.gnu.org/bugs/?func=detailitem&item_id=13606

Best Regards,
Alon Bar-Lev.
-
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/