2018-01-15 11:26:15 +00:00
|
|
|
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
2018-01-06 14:13:39 +00:00
|
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
|
|
|
Date: Sat, 16 Dec 2017 01:14:39 +0100
|
2018-01-15 11:26:15 +00:00
|
|
|
Subject: [PATCH] x86/mm/dump_pagetables: Check PAGE_PRESENT for real
|
2018-01-06 14:13:39 +00:00
|
|
|
MIME-Version: 1.0
|
|
|
|
|
Content-Type: text/plain; charset=UTF-8
|
|
|
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
|
|
|
|
|
|
CVE-2017-5754
|
|
|
|
|
|
|
|
|
|
The check for a present page in printk_prot():
|
|
|
|
|
|
|
|
|
|
if (!pgprot_val(prot)) {
|
|
|
|
|
/* Not present */
|
|
|
|
|
|
|
|
|
|
is bogus. If a PTE is set to PAGE_NONE then the pgprot_val is not zero and
|
|
|
|
|
the entry is decoded in bogus ways, e.g. as RX GLB. That is confusing when
|
|
|
|
|
analyzing mapping correctness. Check for the present bit to make an
|
|
|
|
|
informed decision.
|
|
|
|
|
|
|
|
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
|
|
|
Cc: Andy Lutomirski <luto@kernel.org>
|
|
|
|
|
Cc: Borislav Petkov <bp@alien8.de>
|
|
|
|
|
Cc: Dave Hansen <dave.hansen@linux.intel.com>
|
|
|
|
|
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: linux-kernel@vger.kernel.org
|
|
|
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
|
|
|
(cherry picked from commit c05344947b37f7cda726e802457370bc6eac4d26)
|
|
|
|
|
Signed-off-by: Andy Whitcroft <apw@canonical.com>
|
|
|
|
|
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
|
|
|
|
|
(cherry picked from commit d902780eaea12f23b50be4ff00f8df6157c30e4a)
|
|
|
|
|
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
|
|
|
|
|
---
|
|
|
|
|
arch/x86/mm/dump_pagetables.c | 2 +-
|
|
|
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
|
|
|
|
|
|
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
|
|
|
|
|
index 0470826d2bdc..91aa41c5e0dd 100644
|
|
|
|
|
--- a/arch/x86/mm/dump_pagetables.c
|
|
|
|
|
+++ b/arch/x86/mm/dump_pagetables.c
|
|
|
|
|
@@ -140,7 +140,7 @@ static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg)
|
|
|
|
|
static const char * const level_name[] =
|
|
|
|
|
{ "cr3", "pgd", "pud", "pmd", "pte" };
|
|
|
|
|
|
|
|
|
|
- if (!pgprot_val(prot)) {
|
|
|
|
|
+ if (!(pr & _PAGE_PRESENT)) {
|
|
|
|
|
/* Not present */
|
|
|
|
|
pt_dump_cont_printf(m, dmsg, " ");
|
|
|
|
|
} else {
|
|
|
|
|
--
|
|
|
|
|
2.14.2
|
|
|
|
|
|
