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kasan: integrate the common part of two KASAN tag-based modes

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1. Move kasan_get_free_track() and kasan_set_free_info() into tags.c
   and combine these two functions for SW_TAGS and HW_TAGS kasan mode.

2. Move kasan_get_bug_type() to report_tags.c and make this function
   compatible for SW_TAGS and HW_TAGS kasan mode.

Link: https://lkml.kernel.org/r/20210626100931.22794-3-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kuan-Ying Lee 2021-06-28 19:40:55 -07:00 committed by Linus Torvalds
parent f06f78ab48
commit a0503b8a0b
7 changed files with 112 additions and 113 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
mm/kasan/Makefile
View File

@ -37,5 +37,5 @@ CFLAGS_sw_tags.o := $(CC_FLAGS_KASAN_RUNTIME)
obj-$(CONFIG_KASAN) := common.o report.o
obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quarantine.o
obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o
obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o
obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o tags.o report_tags.o
obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o tags.o report_tags.o

22
mm/kasan/hw_tags.c
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@ -216,28 +216,6 @@ void __init kasan_init_hw_tags(void)
pr_info("KernelAddressSanitizer initialized\n");
}
void kasan_set_free_info(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
alloc_meta = kasan_get_alloc_meta(cache, object);
if (alloc_meta)
kasan_set_track(&alloc_meta->free_track[0], GFP_NOWAIT);
}
struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
alloc_meta = kasan_get_alloc_meta(cache, object);
if (!alloc_meta)
return NULL;
return &alloc_meta->free_track[0];
}
#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
void kasan_set_tagging_report_once(bool state)

5
mm/kasan/report_hw_tags.c
View File

@ -15,11 +15,6 @@
#include "kasan.h"
const char *kasan_get_bug_type(struct kasan_access_info *info)
{
return "invalid-access";
}
void *kasan_find_first_bad_addr(void *addr, size_t size)
{
return kasan_reset_tag(addr);

43
mm/kasan/report_sw_tags.c
View File

@ -29,49 +29,6 @@
#include "kasan.h"
#include "../slab.h"
const char *kasan_get_bug_type(struct kasan_access_info *info)
{
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
struct kasan_alloc_meta *alloc_meta;
struct kmem_cache *cache;
struct page *page;
const void *addr;
void *object;
u8 tag;
int i;
tag = get_tag(info->access_addr);
addr = kasan_reset_tag(info->access_addr);
page = kasan_addr_to_page(addr);
if (page && PageSlab(page)) {
cache = page->slab_cache;
object = nearest_obj(cache, page, (void *)addr);
alloc_meta = kasan_get_alloc_meta(cache, object);
if (alloc_meta) {
for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
if (alloc_meta->free_pointer_tag[i] == tag)
return "use-after-free";
}
}
return "out-of-bounds";
}
#endif
/*
* If access_size is a negative number, then it has reason to be
* defined as out-of-bounds bug type.
*
* Casting negative numbers to size_t would indeed turn up as
* a large size_t and its value will be larger than ULONG_MAX/2,
* so that this can qualify as out-of-bounds.
*/
if (info->access_addr + info->access_size < info->access_addr)
return "out-of-bounds";
return "invalid-access";
}
void *kasan_find_first_bad_addr(void *addr, size_t size)
{
u8 tag = get_tag(addr);

51
mm/kasan/report_tags.c Normal file
View File

@ -0,0 +1,51 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* Copyright (c) 2020 Google, Inc.
*/
#include "kasan.h"
#include "../slab.h"
const char *kasan_get_bug_type(struct kasan_access_info *info)
{
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
struct kasan_alloc_meta *alloc_meta;
struct kmem_cache *cache;
struct page *page;
const void *addr;
void *object;
u8 tag;
int i;
tag = get_tag(info->access_addr);
addr = kasan_reset_tag(info->access_addr);
page = kasan_addr_to_page(addr);
if (page && PageSlab(page)) {
cache = page->slab_cache;
object = nearest_obj(cache, page, (void *)addr);
alloc_meta = kasan_get_alloc_meta(cache, object);
if (alloc_meta) {
for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
if (alloc_meta->free_pointer_tag[i] == tag)
return "use-after-free";
}
}
return "out-of-bounds";
}
#endif
/*
* If access_size is a negative number, then it has reason to be
* defined as out-of-bounds bug type.
*
* Casting negative numbers to size_t would indeed turn up as
* a large size_t and its value will be larger than ULONG_MAX/2,
* so that this can qualify as out-of-bounds.
*/
if (info->access_addr + info->access_size < info->access_addr)
return "out-of-bounds";
return "invalid-access";
}

41
mm/kasan/sw_tags.c
View File

@ -166,44 +166,3 @@ void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
kasan_poison((void *)addr, size, tag, false);
}
EXPORT_SYMBOL(__hwasan_tag_memory);
void kasan_set_free_info(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
u8 idx = 0;
alloc_meta = kasan_get_alloc_meta(cache, object);
if (!alloc_meta)
return;
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
idx = alloc_meta->free_track_idx;
alloc_meta->free_pointer_tag[idx] = tag;
alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
#endif
kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
}
struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
int i = 0;
alloc_meta = kasan_get_alloc_meta(cache, object);
if (!alloc_meta)
return NULL;
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
if (alloc_meta->free_pointer_tag[i] == tag)
break;
}
if (i == KASAN_NR_FREE_STACKS)
i = alloc_meta->free_track_idx;
#endif
return &alloc_meta->free_track[i];
}

59
mm/kasan/tags.c Normal file
View File

@ -0,0 +1,59 @@
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains common tag-based KASAN code.
*
* Copyright (c) 2018 Google, Inc.
* Copyright (c) 2020 Google, Inc.
*/
#include <linux/init.h>
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/static_key.h>
#include <linux/string.h>
#include <linux/types.h>
#include "kasan.h"
void kasan_set_free_info(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
u8 idx = 0;
alloc_meta = kasan_get_alloc_meta(cache, object);
if (!alloc_meta)
return;
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
idx = alloc_meta->free_track_idx;
alloc_meta->free_pointer_tag[idx] = tag;
alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
#endif
kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
}
struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
void *object, u8 tag)
{
struct kasan_alloc_meta *alloc_meta;
int i = 0;
alloc_meta = kasan_get_alloc_meta(cache, object);
if (!alloc_meta)
return NULL;
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
if (alloc_meta->free_pointer_tag[i] == tag)
break;
}
if (i == KASAN_NR_FREE_STACKS)
i = alloc_meta->free_track_idx;
#endif
return &alloc_meta->free_track[i];
}