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From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Florian Weimer <fweimer@redhat.com>, Jann Horn <jannh@google.com>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH v2 7/8] x86/vsyscall: Add __ro_after_init to global variables
Date: Wed, 26 Jun 2019 21:45:08 -0700	[thread overview]
Message-ID: <a386925835e49d319e70c4d7404b1f6c3c2e3702.1561610354.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1561610354.git.luto@kernel.org>

The vDSO is only configurable by command-line options, so make its
global variables __ro_after_init.  This seems highly unlikely to
ever stop an exploit, but I think it's nice anyway.

Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 9c58ab807aeb..07003f3f1bfc 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -42,7 +42,7 @@
 #define CREATE_TRACE_POINTS
 #include "vsyscall_trace.h"
 
-static enum { EMULATE, XONLY, NONE } vsyscall_mode =
+static enum { EMULATE, XONLY, NONE } vsyscall_mode __ro_after_init =
 #ifdef CONFIG_LEGACY_VSYSCALL_NONE
 	NONE;
 #elif defined(CONFIG_LEGACY_VSYSCALL_XONLY)
@@ -305,7 +305,7 @@ static const char *gate_vma_name(struct vm_area_struct *vma)
 static const struct vm_operations_struct gate_vma_ops = {
 	.name = gate_vma_name,
 };
-static struct vm_area_struct gate_vma = {
+static struct vm_area_struct gate_vma __ro_after_init = {
 	.vm_start	= VSYSCALL_ADDR,
 	.vm_end		= VSYSCALL_ADDR + PAGE_SIZE,
 	.vm_page_prot	= PAGE_READONLY_EXEC,
-- 
2.21.0


  parent reply	other threads:[~2019-06-27  4:45 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-27  4:45 [PATCH v2 0/8] vsyscall xonly mode Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 1/8] x86/vsyscall: Remove the vsyscall=native documentation Andy Lutomirski
2019-06-27 17:26   ` Kees Cook
2019-06-27 22:13   ` [tip:x86/entry] Documentation/admin: " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 2/8] x86/vsyscall: Add a new vsyscall=xonly mode Andy Lutomirski
2019-06-27 17:26   ` Kees Cook
2019-06-27 22:13   ` [tip:x86/entry] " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 3/8] x86/vsyscall: Show something useful on a read fault Andy Lutomirski
2019-06-27 17:28   ` Kees Cook
2019-06-27 22:14   ` [tip:x86/entry] " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 4/8] x86/vsyscall: Document odd SIGSEGV error code for vsyscalls Andy Lutomirski
2019-06-27 17:28   ` Kees Cook
2019-06-27 22:15   ` [tip:x86/entry] " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 5/8] selftests/x86/vsyscall: Verify that vsyscall=none blocks execution Andy Lutomirski
2019-06-27 17:29   ` Kees Cook
2019-06-27 22:16   ` [tip:x86/entry] " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 6/8] x86/vsyscall: Change the default vsyscall mode to xonly Andy Lutomirski
2019-06-27 17:30   ` Kees Cook
2019-06-27 22:16   ` [tip:x86/entry] " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` Andy Lutomirski [this message]
2019-06-27 17:30   ` [PATCH v2 7/8] x86/vsyscall: Add __ro_after_init to global variables Kees Cook
2019-06-27 22:17   ` [tip:x86/entry] " tip-bot for Andy Lutomirski
2019-06-27  4:45 ` [PATCH v2 8/8] selftests/x86: Add a test for process_vm_readv() on the vsyscall page Andy Lutomirski
2019-06-27 17:30   ` Kees Cook
2019-06-27 22:18   ` [tip:x86/entry] " tip-bot for Andy Lutomirski

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