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Commit 93f051b0 authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Alex Shi
Browse files

mm: page_alloc: add kasan hooks on alloc and free paths 



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: default avatarAndrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: default avatarAndrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit b8c73fc2493d42517be95cf2c89659fc6c6f4d02)
Signed-off-by: default avatarAlex Shi <alex.shi@linaro.org>
parent c8bbd6b9

include/linux/kasan.h

+6 −0
Original line number Diff line number Diff line
@@ -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 */

mm/compaction.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

	}

}

mm/kasan/kasan.c

+14 −0
Original line number Diff line number Diff line
@@ -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)		\

	{							\

mm/kasan/kasan.h

+2 −0
Original line number Diff line number Diff line
@@ -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;

mm/kasan/report.c

+11 −0
Original line number Diff line number Diff line
@@ -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();

}