From: Kees Cook <keescook@chromium.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>,
Laura Abbott <labbott@redhat.com>,
"the arch/x86 maintainers" <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 04/20] gcc-plugins: Add the randstruct plugin
Date: Thu, 29 Jun 2017 17:04:46 -0700 [thread overview]
Message-ID: <CAGXu5j+P7Sj99DdYE0mL1fjzVUoK6qntJXhSLk-vnKhHjejd7g@mail.gmail.com> (raw)
In-Reply-To: <CAGXu5jJHRC83YSDKVfm4_41k0wgqfG=wpqPQss-ce77SRNkwRA@mail.gmail.com>
On Thu, Jun 29, 2017 at 3:53 PM, Kees Cook <keescook@chromium.org> wrote:
> I see a few possible solutions:
Or this ugly hack:
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e2ad3531e7fe..5d131f9f1dac 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -749,6 +749,19 @@ struct task_struct {
/* Namespaces: */
struct nsproxy *nsproxy;
+#ifdef CONFIG_ARM
+ /*
+ * Since task_struct is gigantic, some asmoffset locations
+ * (e.g. TSK_STACK_CANARY) for a randomized field may exceed
+ * an architecture's instruction immediate values. As a
+ * work-around to avoid changing the performance characteristics
+ * of the assembly, split the randomization into two groups,
+ * keeping the "early" fields within range of the immediates.
+ */
+ randomized_struct_fields_end
+ randomized_struct_fields_start
+#endif
+
/* Signal handlers: */
struct signal_struct *signal;
struct sighand_struct *sighand;
I suspect updating the ARM assembly (CONFIG-conditionally) to accept
>4095 offsets is probably the best solution.
-Kees
--
Kees Cook
Pixel Security
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>,
Laura Abbott <labbott@redhat.com>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [kernel-hardening] Re: [PATCH v2 04/20] gcc-plugins: Add the randstruct plugin
Date: Thu, 29 Jun 2017 17:04:46 -0700 [thread overview]
Message-ID: <CAGXu5j+P7Sj99DdYE0mL1fjzVUoK6qntJXhSLk-vnKhHjejd7g@mail.gmail.com> (raw)
In-Reply-To: <CAGXu5jJHRC83YSDKVfm4_41k0wgqfG=wpqPQss-ce77SRNkwRA@mail.gmail.com>
On Thu, Jun 29, 2017 at 3:53 PM, Kees Cook <keescook@chromium.org> wrote:
> I see a few possible solutions:
Or this ugly hack:
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e2ad3531e7fe..5d131f9f1dac 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -749,6 +749,19 @@ struct task_struct {
/* Namespaces: */
struct nsproxy *nsproxy;
+#ifdef CONFIG_ARM
+ /*
+ * Since task_struct is gigantic, some asmoffset locations
+ * (e.g. TSK_STACK_CANARY) for a randomized field may exceed
+ * an architecture's instruction immediate values. As a
+ * work-around to avoid changing the performance characteristics
+ * of the assembly, split the randomization into two groups,
+ * keeping the "early" fields within range of the immediates.
+ */
+ randomized_struct_fields_end
+ randomized_struct_fields_start
+#endif
+
/* Signal handlers: */
struct signal_struct *signal;
struct sighand_struct *sighand;
I suspect updating the ARM assembly (CONFIG-conditionally) to accept
>4095 offsets is probably the best solution.
-Kees
--
Kees Cook
Pixel Security
next prev parent reply other threads:[~2017-06-30 0:05 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-26 20:17 [PATCH v2 00/20] Introduce struct layout randomization plugin Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 01/20] NFS: Avoid cross-structure casting Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-28 7:53 ` Christoph Hellwig
2017-05-28 7:53 ` [kernel-hardening] " Christoph Hellwig
2017-05-28 16:55 ` Kees Cook
2017-05-28 16:55 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 02/20] gcc-plugins: Detail c-common.h location for GCC 4.6 Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 03/20] compiler: Add __designated_init annotation Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 04/20] gcc-plugins: Add the randstruct plugin Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-06-29 22:08 ` Arnd Bergmann
2017-06-29 22:08 ` [kernel-hardening] " Arnd Bergmann
2017-06-29 22:53 ` Kees Cook
2017-06-29 22:53 ` [kernel-hardening] " Kees Cook
2017-06-30 0:04 ` Kees Cook [this message]
2017-06-30 0:04 ` Kees Cook
2017-06-30 7:35 ` Arnd Bergmann
2017-06-30 7:35 ` [kernel-hardening] " Arnd Bergmann
2017-06-30 7:55 ` Ard Biesheuvel
2017-06-30 7:55 ` [kernel-hardening] " Ard Biesheuvel
2017-06-30 8:27 ` Arnd Bergmann
2017-06-30 8:27 ` [kernel-hardening] " Arnd Bergmann
2017-06-30 14:41 ` Kees Cook
2017-06-30 14:41 ` [kernel-hardening] " Kees Cook
2017-06-30 15:22 ` Arnd Bergmann
2017-06-30 15:22 ` [kernel-hardening] " Arnd Bergmann
2017-05-26 20:17 ` [PATCH v2 05/20] randstruct: Whitelist struct security_hook_heads cast Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-27 8:41 ` Christoph Hellwig
2017-05-27 8:41 ` [kernel-hardening] " Christoph Hellwig
2017-05-27 20:09 ` Kees Cook
2017-05-27 20:09 ` [kernel-hardening] " Kees Cook
2017-05-27 20:09 ` Kees Cook
2017-05-27 22:04 ` Tetsuo Handa
2017-05-27 22:04 ` [kernel-hardening] " Tetsuo Handa
2017-05-27 22:04 ` Tetsuo Handa
2017-05-28 0:43 ` [kernel-hardening] " Kees Cook
2017-05-28 0:43 ` Kees Cook
2017-05-28 0:43 ` Kees Cook
2017-05-30 10:34 ` James Morris
2017-05-30 10:34 ` [kernel-hardening] " James Morris
2017-05-30 10:34 ` James Morris
2017-05-26 20:17 ` [PATCH v2 06/20] randstruct: Whitelist UNIXCB cast Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:20 ` Kees Cook
2017-05-26 20:20 ` [kernel-hardening] " Kees Cook
2017-05-28 7:56 ` Christoph Hellwig
2017-05-28 7:56 ` [kernel-hardening] " Christoph Hellwig
2017-05-26 20:17 ` [PATCH v2 07/20] randstruct: Whitelist big_key path struct overloading Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-28 8:12 ` Christoph Hellwig
2017-05-28 8:12 ` [kernel-hardening] " Christoph Hellwig
2017-05-28 16:59 ` Kees Cook
2017-05-28 16:59 ` [kernel-hardening] " Kees Cook
2017-06-19 19:24 ` Kees Cook
2017-06-19 19:24 ` [kernel-hardening] " Kees Cook
2017-09-07 7:20 ` Christoph Hellwig
2017-09-07 7:20 ` [kernel-hardening] " Christoph Hellwig
2017-09-07 22:55 ` Kees Cook
2017-09-07 22:55 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 08/20] randstruct: Whitelist NIU struct page overloading Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-28 8:15 ` Christoph Hellwig
2017-05-28 8:15 ` [kernel-hardening] " Christoph Hellwig
2017-05-28 17:35 ` Kees Cook
2017-05-28 17:35 ` [kernel-hardening] " Kees Cook
2017-05-28 17:35 ` Kees Cook
2017-05-28 17:37 ` Kees Cook
2017-05-28 17:37 ` [kernel-hardening] " Kees Cook
2017-05-28 17:37 ` Kees Cook
2017-05-26 20:17 ` [PATCH v2 09/20] randstruct: Mark various structs for randomization Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 10/20] randstruct: opt-out externally exposed function pointer structs Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 11/20] randstruct: Disable randomization of ACPICA structs Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-27 8:42 ` Christoph Hellwig
2017-05-27 8:42 ` [kernel-hardening] " Christoph Hellwig
2017-05-27 20:03 ` Kees Cook
2017-05-27 20:03 ` [kernel-hardening] " Kees Cook
2017-05-28 4:55 ` Christoph Hellwig
2017-05-28 4:55 ` [kernel-hardening] " Christoph Hellwig
2017-05-26 20:17 ` [PATCH v2 12/20] sgi-xp: Use designated initializers Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-27 8:44 ` Christoph Hellwig
2017-05-27 8:44 ` [kernel-hardening] " Christoph Hellwig
2017-05-26 20:17 ` [PATCH v2 13/20] drm/amdgpu: " Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 14/20] drm/amd/powerplay: " Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-27 8:47 ` Christoph Hellwig
2017-05-27 8:47 ` [kernel-hardening] " Christoph Hellwig
2017-05-27 20:10 ` Kees Cook
2017-05-27 20:10 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 15/20] mtk-vcodec: " Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 16/20] ntfs: Use ERR_CAST() to avoid cross-structure cast Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 17/20] ocfs2: " Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 18/20] randstruct: Enable function pointer struct detection Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 19/20] [RFC] task_struct: Allow randomized layout Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-26 20:23 ` Linus Torvalds
2017-05-26 20:23 ` [kernel-hardening] " Linus Torvalds
2017-05-26 20:32 ` Kees Cook
2017-05-26 20:32 ` [kernel-hardening] " Kees Cook
2017-05-26 20:17 ` [PATCH v2 20/20] ACPICA: Use designated initializers Kees Cook
2017-05-26 20:17 ` [kernel-hardening] " Kees Cook
2017-05-28 7:45 ` Christoph Hellwig
2017-05-28 7:45 ` [kernel-hardening] " Christoph Hellwig
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