pve-kernel-qoup/patches/kernel/0167-x86-vsyscall-64-Warn-and-fail-vsyscall-emulation-in-.patch
Fabian Grünbichler 59d5af6732 build: reformat existing patches
drop numbers and commit hashes from patch metadata to reduce future
patch churn
2018-01-15 12:26:15 +01:00

56 lines
2.0 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@kernel.org>
Date: Sun, 10 Dec 2017 22:47:20 -0800
Subject: [PATCH] x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE
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CVE-2017-5754
If something goes wrong with pagetable setup, vsyscall=native will
accidentally fall back to emulation. Make it warn and fail so that we
notice.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit 4831b779403a836158917d59a7ca880483c67378)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
(cherry picked from commit ba10c7488b12c3106d79c8b2ba3f4e79c7e40ee4)
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 91f3133cf5f1..5e56a4ced848 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -138,6 +138,10 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
WARN_ON_ONCE(address != regs->ip);
+ /* This should be unreachable in NATIVE mode. */
+ if (WARN_ON(vsyscall_mode == NATIVE))
+ return false;
+
if (vsyscall_mode == NONE) {
warn_bad_vsyscall(KERN_INFO, regs,
"vsyscall attempted with vsyscall=none");
--
2.14.2