140 lines
4.5 KiB
Diff
140 lines
4.5 KiB
Diff
From 2ed23a29f6f9c736c86dcc8d8ab87cc670593503 Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Mon, 4 Dec 2017 15:08:05 +0100
|
|
Subject: [PATCH 216/231] x86/mm/dump_pagetables: Check user space page table
|
|
for WX pages
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
CVE-2017-5754
|
|
|
|
ptdump_walk_pgd_level_checkwx() checks the kernel page table for WX pages,
|
|
but does not check the PAGE_TABLE_ISOLATION user space page table.
|
|
|
|
Restructure the code so that dmesg output is selected by an explicit
|
|
argument and not implicit via checking the pgd argument for !NULL.
|
|
|
|
Add the check for the user space page table.
|
|
|
|
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
|
|
Cc: linux-mm@kvack.org
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
(cherry picked from commit b4bf4f924b1d7bade38fd51b2e401d20d0956e4d)
|
|
Signed-off-by: Andy Whitcroft <apw@canonical.com>
|
|
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
|
|
(cherry picked from commit 1adfe82e8fe5afa2fae59efe498c461d5a52cb6c)
|
|
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
|
|
---
|
|
arch/x86/include/asm/pgtable.h | 1 +
|
|
arch/x86/mm/debug_pagetables.c | 2 +-
|
|
arch/x86/mm/dump_pagetables.c | 30 +++++++++++++++++++++++++-----
|
|
3 files changed, 27 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
|
|
index 25604b8a251a..4f5eb81cf8be 100644
|
|
--- a/arch/x86/include/asm/pgtable.h
|
|
+++ b/arch/x86/include/asm/pgtable.h
|
|
@@ -17,6 +17,7 @@
|
|
#include <asm/x86_init.h>
|
|
|
|
void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd);
|
|
+void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd);
|
|
void ptdump_walk_pgd_level_checkwx(void);
|
|
|
|
#ifdef CONFIG_DEBUG_WX
|
|
diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c
|
|
index d1449fb6dc7a..8e70c1599e51 100644
|
|
--- a/arch/x86/mm/debug_pagetables.c
|
|
+++ b/arch/x86/mm/debug_pagetables.c
|
|
@@ -5,7 +5,7 @@
|
|
|
|
static int ptdump_show(struct seq_file *m, void *v)
|
|
{
|
|
- ptdump_walk_pgd_level(m, NULL);
|
|
+ ptdump_walk_pgd_level_debugfs(m, NULL);
|
|
return 0;
|
|
}
|
|
|
|
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
|
|
index eed93dd4cb4a..7b022ad37c4e 100644
|
|
--- a/arch/x86/mm/dump_pagetables.c
|
|
+++ b/arch/x86/mm/dump_pagetables.c
|
|
@@ -457,7 +457,7 @@ static inline bool is_hypervisor_range(int idx)
|
|
}
|
|
|
|
static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
|
|
- bool checkwx)
|
|
+ bool checkwx, bool dmesg)
|
|
{
|
|
#ifdef CONFIG_X86_64
|
|
pgd_t *start = (pgd_t *) &init_top_pgt;
|
|
@@ -470,7 +470,7 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
|
|
|
|
if (pgd) {
|
|
start = pgd;
|
|
- st.to_dmesg = true;
|
|
+ st.to_dmesg = dmesg;
|
|
}
|
|
|
|
st.check_wx = checkwx;
|
|
@@ -508,13 +508,33 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
|
|
|
|
void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd)
|
|
{
|
|
- ptdump_walk_pgd_level_core(m, pgd, false);
|
|
+ ptdump_walk_pgd_level_core(m, pgd, false, true);
|
|
+}
|
|
+
|
|
+void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd)
|
|
+{
|
|
+ ptdump_walk_pgd_level_core(m, pgd, false, false);
|
|
+}
|
|
+EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs);
|
|
+
|
|
+static void ptdump_walk_user_pgd_level_checkwx(void)
|
|
+{
|
|
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
|
|
+ pgd_t *pgd = (pgd_t *) &init_top_pgt;
|
|
+
|
|
+ if (!static_cpu_has(X86_FEATURE_PTI))
|
|
+ return;
|
|
+
|
|
+ pr_info("x86/mm: Checking user space page tables\n");
|
|
+ pgd = kernel_to_user_pgdp(pgd);
|
|
+ ptdump_walk_pgd_level_core(NULL, pgd, true, false);
|
|
+#endif
|
|
}
|
|
-EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level);
|
|
|
|
void ptdump_walk_pgd_level_checkwx(void)
|
|
{
|
|
- ptdump_walk_pgd_level_core(NULL, NULL, true);
|
|
+ ptdump_walk_pgd_level_core(NULL, NULL, true, false);
|
|
+ ptdump_walk_user_pgd_level_checkwx();
|
|
}
|
|
|
|
static int __init pt_dump_init(void)
|
|
--
|
|
2.14.2
|
|
|