From: David Brown <david.brown@linaro.org>
To: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@arm.linux.org.uk>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
Ingo Molnar <mingo@redhat.com>,
Andy Lutomirski <luto@amacapital.net>,
"H. Peter Anvin" <hpa@zytor.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Mathias Krause <minipli@googlemail.com>,
Thomas Gleixner <tglx@linutronix.de>,
"x86@kernel.org" <x86@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
PaX Team <pageexec@freemail.hu>, Emese Revfy <re.emese@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>
Subject: Re: [PATCH] ARM: vdso: Mark vDSO code as read-only
Date: Tue, 16 Feb 2016 22:20:10 -0700 [thread overview]
Message-ID: <20160217052010.GA49233@davidb.org> (raw)
In-Reply-To: <CAGXu5j+H63jhcDpHpXK5aWvgUBz=5vB0FK_zRoc+wZEk32B2fg@mail.gmail.com>
On Tue, Feb 16, 2016 at 01:52:33PM -0800, Kees Cook wrote:
>On Tue, Feb 16, 2016 at 1:36 PM, David Brown <david.brown@linaro.org> wrote:
>> Although the arm vDSO is cleanly separated by code/data with the code
>> being read-only in userspace mappings, the code page is still writable
>> from the kernel. There have been exploits (such as
>> http://itszn.com/blog/?p=21) that take advantage of this on x86 to go
>> from a bad kernel write to full root.
>>
>> Prevent this specific exploit on arm by putting the vDSO code page in
>> post-init read-only memory as well.
>
>Is the vdso dynamically built at init time like on x86, or can this
>just use .rodata directly?
On ARM, it is patched during init. Arm64's is just plain read-only.
David
next prev parent reply other threads:[~2016-02-17 5:20 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-19 18:08 [PATCH v4 0/8] introduce post-init read-only memory Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 1/8] asm-generic: consolidate mark_rodata_ro() Kees Cook
2016-01-19 18:08 ` [PATCH v4 2/8] lib: add "on" and "off" to strtobool Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-20 2:09 ` Joe Perches
2016-01-22 23:29 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 3/8] param: convert some "on"/"off" users " Kees Cook
2016-01-27 21:11 ` David Brown
2016-01-27 21:11 ` [kernel-hardening] " David Brown
2016-01-27 21:19 ` Kees Cook
2016-01-28 0:09 ` [PATCH] arm64: make CONFIG_DEBUG_RODATA non-optional David Brown
2016-01-28 0:09 ` David Brown
2016-01-28 0:14 ` Kees Cook
2016-01-28 0:14 ` Kees Cook
2016-01-28 8:20 ` Ard Biesheuvel
2016-01-28 8:20 ` Ard Biesheuvel
2016-01-28 11:06 ` Mark Rutland
2016-01-28 11:06 ` Mark Rutland
2016-01-28 14:06 ` Kees Cook
2016-01-28 14:06 ` Kees Cook
2016-01-28 14:59 ` Mark Rutland
2016-01-28 14:59 ` Mark Rutland
2016-01-28 15:17 ` Kees Cook
2016-01-28 15:17 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 4/8] init: create cmdline param to disable readonly Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 5/8] x86: make CONFIG_DEBUG_RODATA non-optional Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 6/8] introduce post-init read-only memory Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 7/8] lkdtm: verify that __ro_after_init works correctly Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-19 18:08 ` [PATCH v4 8/8] x86, vdso: mark vDSO read-only after init Kees Cook
2016-01-19 18:08 ` Kees Cook
2016-01-19 19:09 ` Andy Lutomirski
2016-01-20 2:51 ` H. Peter Anvin
2016-01-20 2:51 ` H. Peter Anvin
2016-01-20 2:56 ` Andy Lutomirski
2016-01-22 17:19 ` [PATCH v4 0/8] introduce post-init read-only memory David Brown
2016-01-22 17:19 ` [kernel-hardening] " David Brown
2016-01-22 19:16 ` Laura Abbott
2016-01-22 19:16 ` Laura Abbott
2016-01-22 19:57 ` Kees Cook
2016-01-23 9:49 ` Geert Uytterhoeven
2016-02-16 21:36 ` [PATCH] ARM: vdso: Mark vDSO code as read-only David Brown
2016-02-16 21:52 ` Kees Cook
2016-02-17 5:20 ` David Brown [this message]
2016-02-17 23:00 ` Kees Cook
2016-02-17 23:43 ` David Brown
2016-02-17 23:43 ` David Brown
2016-02-17 23:48 ` Kees Cook
2016-02-18 10:46 ` PaX Team
2016-02-18 10:46 ` PaX Team
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