[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <468D5B28.8080308@redhat.com>
Date: Thu, 05 Jul 2007 16:57:12 -0400
From: Rik van Riel <riel@...hat.com>
To: Chuck Ebbert <cebbert@...hat.com>
CC: Jiri Kosina <jkosina@...e.cz>, Jakub Jelinek <jakub@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Jan Kratochvil <honza@...os.cz>, Ingo Molnar <mingo@...e.hu>,
linux-kernel@...r.kernel.org, Ernie Petrides <petrides@...hat.com>
Subject: Re: [PATCH][RESEND] PIE randomization
Chuck Ebbert wrote:
> On 07/04/2007 01:35 PM, Jiri Kosina wrote:
>> On Wed, 4 Jul 2007, Jakub Jelinek wrote:
>>
>>> The above highlighted changes are the cause of random segfaults of PIE
>>> binaries. See
>>> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=246623
>> Thanks a lot for pointing this out. Andrew, could this be folded into
>> pie-randomization.patch please?
>>
>>
>> From: Jiri Kosina <jkosina@...e.cz>
>>
>> pie randomization: fix BAD_ADDR macro
>>
>> pie-randomization.patch makes the load_addr in load_elf_interp() the load
>> bias of ld.so (difference between the actual load base address and first
>> PT_LOAD segment's p_vaddr). If the difference equals (on x86) to
>> 0xfffff000 (which is valid [1]), SIGSEGV is incorrectly sent.
>>
>> This patch changes the BAD_ADDR so that it catches the mappings to the
>> error-area properly.
>
> But what about this patch that made the opposite change:
>
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ce51059be56f63762089412b3ece348067afda85
Ohhh, interesting.
So the original patch has:
#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
For some reason(?) it got changed to the clearly buggy:
#define BAD_ADDR(x) ((unsigned long)(x) >= PAGE_MASK)
Jiri's patch undoes that second buggy define, which is very
different from the original that was sent in by you and Ernie.
--
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is. Each group
calls the other unpatriotic.
-
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/
Powered by blists - more mailing lists