[Devel] [PATCH RHEL7 COMMIT] ms/mm: page_alloc: add kasan hooks on alloc and free paths
Konstantin Khorenko
khorenko at virtuozzo.com
Thu Sep 3 08:27:37 PDT 2015
The commit is pushed to "branch-rh7-3.10.0-229.7.2-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.6.6
------>
commit eee3edb3fbf8781f7b4971eca769aa78d0891aa7
Author: Andrey Ryabinin <aryabinin at odin.com>
Date: Thu Sep 3 19:27:37 2015 +0400
ms/mm: page_alloc: add kasan hooks on alloc and free paths
https://jira.sw.ru/browse/PSBM-26429
From: Andrey Ryabinin <a.ryabinin at samsung.com>
commit b8c73fc2493d42517be95cf2c89659fc6c6f4d02 upstream.
Add kernel address sanitizer hooks to mark allocated page's addresses as
accessible in corresponding shadow region. Mark freed pages as
inaccessible.
Signed-off-by: Andrey Ryabinin <a.ryabinin at samsung.com>
Cc: Dmitry Vyukov <dvyukov at google.com>
Cc: Konstantin Serebryany <kcc at google.com>
Cc: Dmitry Chernenkov <dmitryc at google.com>
Signed-off-by: Andrey Konovalov <adech.fo at gmail.com>
Cc: Yuri Gribov <tetra2005 at gmail.com>
Cc: Konstantin Khlebnikov <koct9i at gmail.com>
Cc: Sasha Levin <sasha.levin at oracle.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Cc: Dave Hansen <dave.hansen at intel.com>
Cc: Andi Kleen <andi at firstfloor.org>
Cc: Ingo Molnar <mingo at elte.hu>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: "H. Peter Anvin" <hpa at zytor.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Pekka Enberg <penberg at kernel.org>
Cc: David Rientjes <rientjes at google.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Andrey Ryabinin <aryabinin at odin.com>
Signed-off-by: Andrey Ryabinin <aryabinin at odin.com>
---
include/linux/kasan.h | 6 ++++++
mm/compaction.c | 2 ++
mm/kasan/kasan.c | 14 ++++++++++++++
mm/kasan/kasan.h | 2 ++
mm/kasan/report.c | 11 +++++++++++
mm/page_alloc.c | 3 +++
6 files changed, 38 insertions(+)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 9102fda..f00c15c 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -34,6 +34,9 @@ static inline void kasan_disable_current(void)
void kasan_unpoison_shadow(const void *address, size_t size);
+void kasan_alloc_pages(struct page *page, unsigned int order);
+void kasan_free_pages(struct page *page, unsigned int order);
+
#else /* CONFIG_KASAN */
static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
@@ -41,6 +44,9 @@ static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
static inline void kasan_enable_current(void) {}
static inline void kasan_disable_current(void) {}
+static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
+static inline void kasan_free_pages(struct page *page, unsigned int order) {}
+
#endif /* CONFIG_KASAN */
#endif /* LINUX_KASAN_H */
diff --git a/mm/compaction.c b/mm/compaction.c
index 411b382..6e6908e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -16,6 +16,7 @@
#include <linux/sysfs.h>
#include <linux/balloon_compaction.h>
#include <linux/page-isolation.h>
+#include <linux/kasan.h>
#include "internal.h"
#ifdef CONFIG_COMPACTION
@@ -59,6 +60,7 @@ static void map_pages(struct list_head *list)
list_for_each_entry(page, list, lru) {
arch_alloc_page(page, 0);
kernel_map_pages(page, 1, 1);
+ kasan_alloc_pages(page, 0);
}
}
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index def8110..b516eb8 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -254,6 +254,20 @@ static __always_inline void check_memory_region(unsigned long addr,
kasan_report(addr, size, write, _RET_IP_);
}
+void kasan_alloc_pages(struct page *page, unsigned int order)
+{
+ if (likely(!PageHighMem(page)))
+ kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
+}
+
+void kasan_free_pages(struct page *page, unsigned int order)
+{
+ if (likely(!PageHighMem(page)))
+ kasan_poison_shadow(page_address(page),
+ PAGE_SIZE << order,
+ KASAN_FREE_PAGE);
+}
+
#define DEFINE_ASAN_LOAD_STORE(size) \
void __asan_load##size(unsigned long addr) \
{ \
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 648b9c0..d3c90d5 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -6,6 +6,8 @@
#define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
#define KASAN_SHADOW_MASK (KASAN_SHADOW_SCALE_SIZE - 1)
+#define KASAN_FREE_PAGE 0xFF /* page was freed */
+
struct kasan_access_info {
const void *access_addr;
const void *first_bad_addr;
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 5835d69..fab8e78 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -54,6 +54,9 @@ static void print_error_description(struct kasan_access_info *info)
shadow_val = *(u8 *)kasan_mem_to_shadow(info->first_bad_addr);
switch (shadow_val) {
+ case KASAN_FREE_PAGE:
+ bug_type = "use after free";
+ break;
case 0 ... KASAN_SHADOW_SCALE_SIZE - 1:
bug_type = "out of bounds access";
break;
@@ -69,6 +72,14 @@ static void print_error_description(struct kasan_access_info *info)
static void print_address_description(struct kasan_access_info *info)
{
+ const void *addr = info->access_addr;
+
+ if ((addr >= (void *)PAGE_OFFSET) &&
+ (addr < high_memory)) {
+ struct page *page = virt_to_head_page(addr);
+ dump_page(page, "kasan: bad access detected");
+ }
+
dump_stack();
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2d968a5..ce719f8c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -25,6 +25,7 @@
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/kmemcheck.h>
+#include <linux/kasan.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
@@ -727,6 +728,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order)
trace_mm_page_free(page, order);
kmemcheck_free_shadow(page, order);
+ kasan_free_pages(page, order);
if (PageAnon(page))
page->mapping = NULL;
@@ -894,6 +896,7 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
set_page_private(page, 0);
arch_alloc_page(page, order);
kernel_map_pages(page, 1 << order, 1);
+ kasan_alloc_pages(page, order);
if (gfp_flags & __GFP_ZERO)
prep_zero_page(page, order, gfp_flags);
More information about the Devel
mailing list