From: Solar Designer <solar@openwall.com>
To: kernel-hardening@lists.openwall.com
Subject: Re: [kernel-hardening] [RFC] x86, mm: start mmap allocation for libs from low addresses
Date: Wed, 7 Sep 2011 13:30:36 +0400 [thread overview]
Message-ID: <20110907093036.GA17693@openwall.com> (raw)
In-Reply-To: <20110907090900.GA3910@albatros>
Vasiliy,
On Wed, Sep 07, 2011 at 01:09:00PM +0400, Vasiliy Kulikov wrote:
> I've updated patch description, code comments, and "if" condition. If
> no other objection, I'll post it as RFCv2 on LKML.
I've included some minor corrections below. Please make changes
accordingly and post to LKML.
> +#ifdef CONFIG_VM86
> +/*
> + * Don't touch any memory that can be addressed by vm86 apps.
> + * Reserve the first 1 MiB + 64 kb.
> + */
> +#define ASCII_ARMOR_MIN_ADDR 0x00110000
> +#else
> +/* No special users of low addresses. Start just after mmap_min_addr. */
> +#define ASCII_ARMOR_MIN_ADDR 0
> +#endif
What if mmap_min_addr set really low, or is even 0? I think we want to
skip low addresses even if processes are permitted to use those.
(Permitted does not mean encouraged.) So how about ASCII_ARMOR_MIN_ADDR
0x19000 (100 KB) when !CONFIG_VM86?
> + /* We ALWAYS start from the beginning as base addresses
> + * with zero high bits is a valued resource */
s/valued/scarce and valuable/
> + * If kernel.randomize_va_space < 2, the executable is build as
s/build/built/
Thanks,
Alexander
next prev parent reply other threads:[~2011-09-07 9:30 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-12 10:29 [kernel-hardening] [RFC] x86, mm: start mmap allocation for libs from low addresses Vasiliy Kulikov
2011-08-12 10:58 ` Solar Designer
2011-08-12 11:05 ` Vasiliy Kulikov
2011-08-25 17:19 ` Vasiliy Kulikov
2011-08-25 17:39 ` Solar Designer
2011-09-02 18:29 ` Solar Designer
2011-09-03 11:18 ` Vasiliy Kulikov
2011-09-03 23:57 ` Solar Designer
2011-09-05 12:46 ` Vasiliy Kulikov
2011-09-06 5:05 ` Solar Designer
2011-09-07 9:09 ` Vasiliy Kulikov
2011-09-07 9:30 ` Solar Designer [this message]
2011-09-07 9:34 ` Vasiliy Kulikov
2011-09-07 9:43 ` Solar Designer
2011-09-07 9:55 ` Vasiliy Kulikov
2011-09-07 10:16 ` Solar Designer
2011-09-07 11:01 ` Vasiliy Kulikov
2011-09-02 23:34 ` Solar Designer
2011-09-03 12:12 ` Vasiliy Kulikov
2011-09-03 23:40 ` Solar Designer
2011-09-04 7:21 ` Vasiliy Kulikov
2011-08-12 23:19 ` [kernel-hardening] " H. Peter Anvin
2011-08-13 6:26 ` Vasiliy Kulikov
2011-08-16 9:05 ` Vasiliy Kulikov
2011-08-22 10:17 ` Vasiliy Kulikov
2011-08-22 17:24 ` H. Peter Anvin
2011-08-22 20:14 ` Vasiliy Kulikov
2011-08-22 20:17 ` H. Peter Anvin
2011-08-23 6:41 ` Vasiliy Kulikov
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