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Message-id: <1410359487-31938-4-git-send-email-a.ryabinin@samsung.com>
Date: Wed, 10 Sep 2014 18:31:20 +0400
From: Andrey Ryabinin <a.ryabinin@...sung.com>
To: linux-kernel@...r.kernel.org
Cc: Andrey Ryabinin <a.ryabinin@...sung.com>,
Dmitry Vyukov <dvyukov@...gle.com>,
Konstantin Serebryany <kcc@...gle.com>,
Dmitry Chernenkov <dmitryc@...gle.com>,
Andrey Konovalov <adech.fo@...il.com>,
Yuri Gribov <tetra2005@...il.com>,
Konstantin Khlebnikov <koct9i@...il.com>,
Sasha Levin <sasha.levin@...cle.com>,
Christoph Lameter <cl@...ux.com>,
Joonsoo Kim <iamjoonsoo.kim@....com>,
Andrew Morton <akpm@...ux-foundation.org>,
Dave Hansen <dave.hansen@...el.com>,
Andi Kleen <andi@...stfloor.org>,
Vegard Nossum <vegard.nossum@...il.com>,
"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
linux-mm@...ck.org
Subject: [RFC/PATCH v2 03/10] mm: page_alloc: add kasan hooks on alloc and free
pathes
Add kernel address sanitizer hooks to mark allocated page's addresses
as accessible in corresponding shadow region.
Mark freed pages as unaccessible.
Signed-off-by: Andrey Ryabinin <a.ryabinin@...sung.com>
---
include/linux/kasan.h | 6 ++++++
mm/compaction.c | 2 ++
mm/kasan/kasan.c | 14 ++++++++++++++
mm/kasan/kasan.h | 1 +
mm/kasan/report.c | 7 +++++++
mm/page_alloc.c | 3 +++
6 files changed, 33 insertions(+)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index f957ee9..c5ae971 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -31,6 +31,9 @@ static inline void kasan_disable_local(void)
void kasan_unpoison_shadow(const void *address, size_t size);
void kasan_map_shadow(void);
+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) {}
@@ -40,6 +43,9 @@ static inline void kasan_disable_local(void) {}
static inline void kasan_map_shadow(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 7d9d92e..a8c5d6d 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 65f8145..ed4e925 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -109,6 +109,20 @@ static __always_inline void check_memory_region(unsigned long addr,
kasan_report_error(&info);
}
+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);
+}
+
void __asan_load1(unsigned long addr)
{
check_memory_region(addr, 1, false);
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 2ea2ed7..227e9c6 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -6,6 +6,7 @@
#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 */
#define KASAN_SHADOW_GAP 0xF9 /* address belongs to shadow memory */
struct access_info {
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 3bfc8b6..94d79e7 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -57,6 +57,9 @@ static void print_error_description(struct access_info *info)
case 0 ... KASAN_SHADOW_SCALE_SIZE - 1:
bug_type = "out of bounds access";
break;
+ case KASAN_FREE_PAGE:
+ bug_type = "use after free";
+ break;
case KASAN_SHADOW_GAP:
bug_type = "wild memory access";
break;
@@ -78,6 +81,10 @@ static void print_address_description(struct access_info *info)
page = virt_to_head_page((void *)info->access_addr);
switch (shadow_val) {
+ case KASAN_FREE_PAGE:
+ dump_page(page, "kasan error");
+ dump_stack();
+ break;
case KASAN_SHADOW_GAP:
pr_err("No metainfo is available for this access.\n");
dump_stack();
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3935c9a..63c55c9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -61,6 +61,7 @@
#include <linux/page-debug-flags.h>
#include <linux/hugetlb.h>
#include <linux/sched/rt.h>
+#include <linux/kasan.h>
#include <asm/sections.h>
#include <asm/tlbflush.h>
@@ -753,6 +754,7 @@ 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;
@@ -932,6 +934,7 @@ static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags)
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);
--
1.8.5.5
--
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