linux_dsm_epyc7002/include/linux/kasan.h
Walter Wu 8cceeff48f kasan: detect negative size in memory operation function
Patch series "fix the missing underflow in memory operation function", v4.

The patchset helps to produce a KASAN report when size is negative in
memory operation functions.  It is helpful for programmer to solve an
undefined behavior issue.  Patch 1 based on Dmitry's review and
suggestion, patch 2 is a test in order to verify the patch 1.

[1]https://bugzilla.kernel.org/show_bug.cgi?id=199341
[2]https://lore.kernel.org/linux-arm-kernel/20190927034338.15813-1-walter-zh.wu@mediatek.com/

This patch (of 2):

KASAN missed detecting size is a negative number in memset(), memcpy(),
and memmove(), it will cause out-of-bounds bug.  So needs to be detected
by KASAN.

If size is a negative number, then it has a 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.

KASAN report is shown below:

 BUG: KASAN: out-of-bounds in kmalloc_memmove_invalid_size+0x70/0xa0
 Read of size 18446744073709551608 at addr ffffff8069660904 by task cat/72

 CPU: 2 PID: 72 Comm: cat Not tainted 5.4.0-rc1-next-20191004ajb-00001-gdb8af2f372b2-dirty #1
 Hardware name: linux,dummy-virt (DT)
 Call trace:
  dump_backtrace+0x0/0x288
  show_stack+0x14/0x20
  dump_stack+0x10c/0x164
  print_address_description.isra.9+0x68/0x378
  __kasan_report+0x164/0x1a0
  kasan_report+0xc/0x18
  check_memory_region+0x174/0x1d0
  memmove+0x34/0x88
  kmalloc_memmove_invalid_size+0x70/0xa0

[1] https://bugzilla.kernel.org/show_bug.cgi?id=199341

[cai@lca.pw: fix -Wdeclaration-after-statement warn]
  Link: http://lkml.kernel.org/r/1583509030-27939-1-git-send-email-cai@lca.pw
[peterz@infradead.org: fix objtool warning]
  Link: http://lkml.kernel.org/r/20200305095436.GV2596@hirez.programming.kicks-ass.net
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Link: http://lkml.kernel.org/r/20191112065302.7015-1-walter-zh.wu@mediatek.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:30 -07:00

238 lines
7.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KASAN_H
#define _LINUX_KASAN_H
#include <linux/types.h>
struct kmem_cache;
struct page;
struct vm_struct;
struct task_struct;
#ifdef CONFIG_KASAN
#include <asm/kasan.h>
#include <asm/pgtable.h>
extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE];
extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD];
extern pud_t kasan_early_shadow_pud[PTRS_PER_PUD];
extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
int kasan_populate_early_shadow(const void *shadow_start,
const void *shadow_end);
static inline void *kasan_mem_to_shadow(const void *addr)
{
return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
+ KASAN_SHADOW_OFFSET;
}
/* Enable reporting bugs after kasan_disable_current() */
extern void kasan_enable_current(void);
/* Disable reporting bugs for current task */
extern void kasan_disable_current(void);
void kasan_unpoison_shadow(const void *address, size_t size);
void kasan_unpoison_task_stack(struct task_struct *task);
void kasan_unpoison_stack_above_sp_to(const void *watermark);
void kasan_alloc_pages(struct page *page, unsigned int order);
void kasan_free_pages(struct page *page, unsigned int order);
void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
slab_flags_t *flags);
void kasan_poison_slab(struct page *page);
void kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
void kasan_poison_object_data(struct kmem_cache *cache, void *object);
void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
const void *object);
void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
gfp_t flags);
void kasan_kfree_large(void *ptr, unsigned long ip);
void kasan_poison_kfree(void *ptr, unsigned long ip);
void * __must_check kasan_kmalloc(struct kmem_cache *s, const void *object,
size_t size, gfp_t flags);
void * __must_check kasan_krealloc(const void *object, size_t new_size,
gfp_t flags);
void * __must_check kasan_slab_alloc(struct kmem_cache *s, void *object,
gfp_t flags);
bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip);
struct kasan_cache {
int alloc_meta_offset;
int free_meta_offset;
};
/*
* These functions provide a special case to support backing module
* allocations with real shadow memory. With KASAN vmalloc, the special
* case is unnecessary, as the work is handled in the generic case.
*/
#ifndef CONFIG_KASAN_VMALLOC
int kasan_module_alloc(void *addr, size_t size);
void kasan_free_shadow(const struct vm_struct *vm);
#else
static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
static inline void kasan_free_shadow(const struct vm_struct *vm) {}
#endif
int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);
size_t __ksize(const void *);
static inline void kasan_unpoison_slab(const void *ptr)
{
kasan_unpoison_shadow(ptr, __ksize(ptr));
}
size_t kasan_metadata_size(struct kmem_cache *cache);
bool kasan_save_enable_multi_shot(void);
void kasan_restore_multi_shot(bool enabled);
#else /* CONFIG_KASAN */
static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
static inline void kasan_unpoison_stack_above_sp_to(const void *watermark) {}
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) {}
static inline void kasan_cache_create(struct kmem_cache *cache,
unsigned int *size,
slab_flags_t *flags) {}
static inline void kasan_poison_slab(struct page *page) {}
static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
void *object) {}
static inline void kasan_poison_object_data(struct kmem_cache *cache,
void *object) {}
static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
const void *object)
{
return (void *)object;
}
static inline void *kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags)
{
return ptr;
}
static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {}
static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
size_t size, gfp_t flags)
{
return (void *)object;
}
static inline void *kasan_krealloc(const void *object, size_t new_size,
gfp_t flags)
{
return (void *)object;
}
static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
gfp_t flags)
{
return object;
}
static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
unsigned long ip)
{
return false;
}
static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
static inline void kasan_free_shadow(const struct vm_struct *vm) {}
static inline int kasan_add_zero_shadow(void *start, unsigned long size)
{
return 0;
}
static inline void kasan_remove_zero_shadow(void *start,
unsigned long size)
{}
static inline void kasan_unpoison_slab(const void *ptr) { }
static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
#endif /* CONFIG_KASAN */
#ifdef CONFIG_KASAN_GENERIC
#define KASAN_SHADOW_INIT 0
void kasan_cache_shrink(struct kmem_cache *cache);
void kasan_cache_shutdown(struct kmem_cache *cache);
#else /* CONFIG_KASAN_GENERIC */
static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
#endif /* CONFIG_KASAN_GENERIC */
#ifdef CONFIG_KASAN_SW_TAGS
#define KASAN_SHADOW_INIT 0xFF
void kasan_init_tags(void);
void *kasan_reset_tag(const void *addr);
bool kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip);
#else /* CONFIG_KASAN_SW_TAGS */
static inline void kasan_init_tags(void) { }
static inline void *kasan_reset_tag(const void *addr)
{
return (void *)addr;
}
#endif /* CONFIG_KASAN_SW_TAGS */
#ifdef CONFIG_KASAN_VMALLOC
int kasan_populate_vmalloc(unsigned long addr, unsigned long size);
void kasan_poison_vmalloc(const void *start, unsigned long size);
void kasan_unpoison_vmalloc(const void *start, unsigned long size);
void kasan_release_vmalloc(unsigned long start, unsigned long end,
unsigned long free_region_start,
unsigned long free_region_end);
#else
static inline int kasan_populate_vmalloc(unsigned long start,
unsigned long size)
{
return 0;
}
static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
{ }
static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size)
{ }
static inline void kasan_release_vmalloc(unsigned long start,
unsigned long end,
unsigned long free_region_start,
unsigned long free_region_end) {}
#endif
#ifdef CONFIG_KASAN_INLINE
void kasan_non_canonical_hook(unsigned long addr);
#else /* CONFIG_KASAN_INLINE */
static inline void kasan_non_canonical_hook(unsigned long addr) { }
#endif /* CONFIG_KASAN_INLINE */
#endif /* LINUX_KASAN_H */