633c5ed17f
this causes kernel OOPS and upstream is unresponsive about it. see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1726519
75 lines
2.4 KiB
Diff
75 lines
2.4 KiB
Diff
From 9b8667a59df870d8f965d6681cb18843302c8510 Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Mon, 4 Dec 2017 15:07:47 +0100
|
|
Subject: [PATCH 200/242] x86/mm/pti: Share entry text PMD
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
CVE-2017-5754
|
|
|
|
Share the entry text PMD of the kernel mapping with the user space
|
|
mapping. If large pages are enabled this is a single PMD entry and at the
|
|
point where it is copied into the user page table the RW bit has not been
|
|
cleared yet. Clear it right away so the user space visible map becomes RX.
|
|
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Cc: Andy Lutomirski <luto@kernel.org>
|
|
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
|
|
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: Denys Vlasenko <dvlasenk@redhat.com>
|
|
Cc: Eduardo Valentin <eduval@amazon.com>
|
|
Cc: Greg KH <gregkh@linuxfoundation.org>
|
|
Cc: H. Peter Anvin <hpa@zytor.com>
|
|
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
|
|
Cc: Juergen Gross <jgross@suse.com>
|
|
Cc: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Cc: Peter Zijlstra <peterz@infradead.org>
|
|
Cc: Will Deacon <will.deacon@arm.com>
|
|
Cc: aliguori@amazon.com
|
|
Cc: daniel.gruss@iaik.tugraz.at
|
|
Cc: hughd@google.com
|
|
Cc: keescook@google.com
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
(cherry picked from commit 6dc72c3cbca0580642808d677181cad4c6433893)
|
|
Signed-off-by: Andy Whitcroft <apw@canonical.com>
|
|
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
|
|
(cherry picked from commit ee98d7446b4a7c12a57a38b1a5f51e3df0ac2cf3)
|
|
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
|
|
---
|
|
arch/x86/mm/pti.c | 10 ++++++++++
|
|
1 file changed, 10 insertions(+)
|
|
|
|
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
|
|
index 59290356f19f..0e78797650a7 100644
|
|
--- a/arch/x86/mm/pti.c
|
|
+++ b/arch/x86/mm/pti.c
|
|
@@ -287,6 +287,15 @@ static void __init pti_clone_user_shared(void)
|
|
pti_clone_p4d(CPU_ENTRY_AREA_BASE);
|
|
}
|
|
|
|
+/*
|
|
+ * Clone the populated PMDs of the entry and irqentry text and force it RO.
|
|
+ */
|
|
+static void __init pti_clone_entry_text(void)
|
|
+{
|
|
+ pti_clone_pmds((unsigned long) __entry_text_start,
|
|
+ (unsigned long) __irqentry_text_end, _PAGE_RW);
|
|
+}
|
|
+
|
|
/*
|
|
* Initialize kernel page table isolation
|
|
*/
|
|
@@ -298,4 +307,5 @@ void __init pti_init(void)
|
|
pr_info("enabled\n");
|
|
|
|
pti_clone_user_shared();
|
|
+ pti_clone_entry_text();
|
|
}
|
|
--
|
|
2.14.2
|
|
|