1 // SPDX-License-Identifier: GPL-2.0-only
4 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
5 * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
8 #define pr_fmt(fmt) "kasan test: %s " fmt, __func__
10 #include <linux/bitops.h>
11 #include <linux/delay.h>
12 #include <linux/kasan.h>
13 #include <linux/kernel.h>
15 #include <linux/mman.h>
16 #include <linux/module.h>
17 #include <linux/printk.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/uaccess.h>
26 * Note: test functions are marked noinline so that their names appear in
30 static noinline
void __init
kmalloc_oob_right(void)
35 pr_info("out-of-bounds to right\n");
36 ptr
= kmalloc(size
, GFP_KERNEL
);
38 pr_err("Allocation failed\n");
46 static noinline
void __init
kmalloc_oob_left(void)
51 pr_info("out-of-bounds to left\n");
52 ptr
= kmalloc(size
, GFP_KERNEL
);
54 pr_err("Allocation failed\n");
62 static noinline
void __init
kmalloc_node_oob_right(void)
67 pr_info("kmalloc_node(): out-of-bounds to right\n");
68 ptr
= kmalloc_node(size
, GFP_KERNEL
, 0);
70 pr_err("Allocation failed\n");
79 static noinline
void __init
kmalloc_pagealloc_oob_right(void)
82 size_t size
= KMALLOC_MAX_CACHE_SIZE
+ 10;
84 /* Allocate a chunk that does not fit into a SLUB cache to trigger
85 * the page allocator fallback.
87 pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
88 ptr
= kmalloc(size
, GFP_KERNEL
);
90 pr_err("Allocation failed\n");
98 static noinline
void __init
kmalloc_pagealloc_uaf(void)
101 size_t size
= KMALLOC_MAX_CACHE_SIZE
+ 10;
103 pr_info("kmalloc pagealloc allocation: use-after-free\n");
104 ptr
= kmalloc(size
, GFP_KERNEL
);
106 pr_err("Allocation failed\n");
114 static noinline
void __init
kmalloc_pagealloc_invalid_free(void)
117 size_t size
= KMALLOC_MAX_CACHE_SIZE
+ 10;
119 pr_info("kmalloc pagealloc allocation: invalid-free\n");
120 ptr
= kmalloc(size
, GFP_KERNEL
);
122 pr_err("Allocation failed\n");
130 static noinline
void __init
kmalloc_large_oob_right(void)
133 size_t size
= KMALLOC_MAX_CACHE_SIZE
- 256;
134 /* Allocate a chunk that is large enough, but still fits into a slab
135 * and does not trigger the page allocator fallback in SLUB.
137 pr_info("kmalloc large allocation: out-of-bounds to right\n");
138 ptr
= kmalloc(size
, GFP_KERNEL
);
140 pr_err("Allocation failed\n");
148 static noinline
void __init
kmalloc_oob_krealloc_more(void)
154 pr_info("out-of-bounds after krealloc more\n");
155 ptr1
= kmalloc(size1
, GFP_KERNEL
);
156 ptr2
= krealloc(ptr1
, size2
, GFP_KERNEL
);
157 if (!ptr1
|| !ptr2
) {
158 pr_err("Allocation failed\n");
168 static noinline
void __init
kmalloc_oob_krealloc_less(void)
174 pr_info("out-of-bounds after krealloc less\n");
175 ptr1
= kmalloc(size1
, GFP_KERNEL
);
176 ptr2
= krealloc(ptr1
, size2
, GFP_KERNEL
);
177 if (!ptr1
|| !ptr2
) {
178 pr_err("Allocation failed\n");
186 static noinline
void __init
kmalloc_oob_16(void)
192 pr_info("kmalloc out-of-bounds for 16-bytes access\n");
193 ptr1
= kmalloc(sizeof(*ptr1
) - 3, GFP_KERNEL
);
194 ptr2
= kmalloc(sizeof(*ptr2
), GFP_KERNEL
);
195 if (!ptr1
|| !ptr2
) {
196 pr_err("Allocation failed\n");
206 static noinline
void __init
kmalloc_oob_memset_2(void)
211 pr_info("out-of-bounds in memset2\n");
212 ptr
= kmalloc(size
, GFP_KERNEL
);
214 pr_err("Allocation failed\n");
222 static noinline
void __init
kmalloc_oob_memset_4(void)
227 pr_info("out-of-bounds in memset4\n");
228 ptr
= kmalloc(size
, GFP_KERNEL
);
230 pr_err("Allocation failed\n");
239 static noinline
void __init
kmalloc_oob_memset_8(void)
244 pr_info("out-of-bounds in memset8\n");
245 ptr
= kmalloc(size
, GFP_KERNEL
);
247 pr_err("Allocation failed\n");
255 static noinline
void __init
kmalloc_oob_memset_16(void)
260 pr_info("out-of-bounds in memset16\n");
261 ptr
= kmalloc(size
, GFP_KERNEL
);
263 pr_err("Allocation failed\n");
267 memset(ptr
+1, 0, 16);
271 static noinline
void __init
kmalloc_oob_in_memset(void)
276 pr_info("out-of-bounds in memset\n");
277 ptr
= kmalloc(size
, GFP_KERNEL
);
279 pr_err("Allocation failed\n");
283 memset(ptr
, 0, size
+5);
287 static noinline
void __init
kmalloc_uaf(void)
292 pr_info("use-after-free\n");
293 ptr
= kmalloc(size
, GFP_KERNEL
);
295 pr_err("Allocation failed\n");
303 static noinline
void __init
kmalloc_uaf_memset(void)
308 pr_info("use-after-free in memset\n");
309 ptr
= kmalloc(size
, GFP_KERNEL
);
311 pr_err("Allocation failed\n");
316 memset(ptr
, 0, size
);
319 static noinline
void __init
kmalloc_uaf2(void)
324 pr_info("use-after-free after another kmalloc\n");
325 ptr1
= kmalloc(size
, GFP_KERNEL
);
327 pr_err("Allocation failed\n");
332 ptr2
= kmalloc(size
, GFP_KERNEL
);
334 pr_err("Allocation failed\n");
340 pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
344 static noinline
void __init
kfree_via_page(void)
349 unsigned long offset
;
351 pr_info("invalid-free false positive (via page)\n");
352 ptr
= kmalloc(size
, GFP_KERNEL
);
354 pr_err("Allocation failed\n");
358 page
= virt_to_page(ptr
);
359 offset
= offset_in_page(ptr
);
360 kfree(page_address(page
) + offset
);
363 static noinline
void __init
kfree_via_phys(void)
369 pr_info("invalid-free false positive (via phys)\n");
370 ptr
= kmalloc(size
, GFP_KERNEL
);
372 pr_err("Allocation failed\n");
376 phys
= virt_to_phys(ptr
);
377 kfree(phys_to_virt(phys
));
380 static noinline
void __init
kmem_cache_oob(void)
384 struct kmem_cache
*cache
= kmem_cache_create("test_cache",
388 pr_err("Cache allocation failed\n");
391 pr_info("out-of-bounds in kmem_cache_alloc\n");
392 p
= kmem_cache_alloc(cache
, GFP_KERNEL
);
394 pr_err("Allocation failed\n");
395 kmem_cache_destroy(cache
);
400 kmem_cache_free(cache
, p
);
401 kmem_cache_destroy(cache
);
404 static noinline
void __init
memcg_accounted_kmem_cache(void)
409 struct kmem_cache
*cache
;
411 cache
= kmem_cache_create("test_cache", size
, 0, SLAB_ACCOUNT
, NULL
);
413 pr_err("Cache allocation failed\n");
417 pr_info("allocate memcg accounted object\n");
419 * Several allocations with a delay to allow for lazy per memcg kmem
422 for (i
= 0; i
< 5; i
++) {
423 p
= kmem_cache_alloc(cache
, GFP_KERNEL
);
427 kmem_cache_free(cache
, p
);
432 kmem_cache_destroy(cache
);
435 static char global_array
[10];
437 static noinline
void __init
kasan_global_oob(void)
440 char *p
= &global_array
[ARRAY_SIZE(global_array
) + i
];
442 pr_info("out-of-bounds global variable\n");
446 static noinline
void __init
kasan_stack_oob(void)
448 char stack_array
[10];
450 char *p
= &stack_array
[ARRAY_SIZE(stack_array
) + i
];
452 pr_info("out-of-bounds on stack\n");
456 static noinline
void __init
ksize_unpoisons_memory(void)
459 size_t size
= 123, real_size
;
461 pr_info("ksize() unpoisons the whole allocated chunk\n");
462 ptr
= kmalloc(size
, GFP_KERNEL
);
464 pr_err("Allocation failed\n");
467 real_size
= ksize(ptr
);
468 /* This access doesn't trigger an error. */
471 ptr
[real_size
] = 'y';
475 static noinline
void __init
copy_user_test(void)
478 char __user
*usermem
;
482 kmem
= kmalloc(size
, GFP_KERNEL
);
486 usermem
= (char __user
*)vm_mmap(NULL
, 0, PAGE_SIZE
,
487 PROT_READ
| PROT_WRITE
| PROT_EXEC
,
488 MAP_ANONYMOUS
| MAP_PRIVATE
, 0);
489 if (IS_ERR(usermem
)) {
490 pr_err("Failed to allocate user memory\n");
495 pr_info("out-of-bounds in copy_from_user()\n");
496 unused
= copy_from_user(kmem
, usermem
, size
+ 1);
498 pr_info("out-of-bounds in copy_to_user()\n");
499 unused
= copy_to_user(usermem
, kmem
, size
+ 1);
501 pr_info("out-of-bounds in __copy_from_user()\n");
502 unused
= __copy_from_user(kmem
, usermem
, size
+ 1);
504 pr_info("out-of-bounds in __copy_to_user()\n");
505 unused
= __copy_to_user(usermem
, kmem
, size
+ 1);
507 pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
508 unused
= __copy_from_user_inatomic(kmem
, usermem
, size
+ 1);
510 pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
511 unused
= __copy_to_user_inatomic(usermem
, kmem
, size
+ 1);
513 pr_info("out-of-bounds in strncpy_from_user()\n");
514 unused
= strncpy_from_user(kmem
, usermem
, size
+ 1);
516 vm_munmap((unsigned long)usermem
, PAGE_SIZE
);
520 static noinline
void __init
kasan_alloca_oob_left(void)
523 char alloca_array
[i
];
524 char *p
= alloca_array
- 1;
526 pr_info("out-of-bounds to left on alloca\n");
530 static noinline
void __init
kasan_alloca_oob_right(void)
533 char alloca_array
[i
];
534 char *p
= alloca_array
+ i
;
536 pr_info("out-of-bounds to right on alloca\n");
540 static noinline
void __init
kmem_cache_double_free(void)
544 struct kmem_cache
*cache
;
546 cache
= kmem_cache_create("test_cache", size
, 0, 0, NULL
);
548 pr_err("Cache allocation failed\n");
551 pr_info("double-free on heap object\n");
552 p
= kmem_cache_alloc(cache
, GFP_KERNEL
);
554 pr_err("Allocation failed\n");
555 kmem_cache_destroy(cache
);
559 kmem_cache_free(cache
, p
);
560 kmem_cache_free(cache
, p
);
561 kmem_cache_destroy(cache
);
564 static noinline
void __init
kmem_cache_invalid_free(void)
568 struct kmem_cache
*cache
;
570 cache
= kmem_cache_create("test_cache", size
, 0, SLAB_TYPESAFE_BY_RCU
,
573 pr_err("Cache allocation failed\n");
576 pr_info("invalid-free of heap object\n");
577 p
= kmem_cache_alloc(cache
, GFP_KERNEL
);
579 pr_err("Allocation failed\n");
580 kmem_cache_destroy(cache
);
584 /* Trigger invalid free, the object doesn't get freed */
585 kmem_cache_free(cache
, p
+ 1);
588 * Properly free the object to prevent the "Objects remaining in
589 * test_cache on __kmem_cache_shutdown" BUG failure.
591 kmem_cache_free(cache
, p
);
593 kmem_cache_destroy(cache
);
596 static noinline
void __init
kasan_memchr(void)
601 pr_info("out-of-bounds in memchr\n");
602 ptr
= kmalloc(size
, GFP_KERNEL
| __GFP_ZERO
);
606 memchr(ptr
, '1', size
+ 1);
610 static noinline
void __init
kasan_memcmp(void)
616 pr_info("out-of-bounds in memcmp\n");
617 ptr
= kmalloc(size
, GFP_KERNEL
| __GFP_ZERO
);
621 memset(arr
, 0, sizeof(arr
));
622 memcmp(ptr
, arr
, size
+1);
626 static noinline
void __init
kasan_strings(void)
631 pr_info("use-after-free in strchr\n");
632 ptr
= kmalloc(size
, GFP_KERNEL
| __GFP_ZERO
);
639 * Try to cause only 1 invalid access (less spam in dmesg).
640 * For that we need ptr to point to zeroed byte.
641 * Skip metadata that could be stored in freed object so ptr
642 * will likely point to zeroed byte.
647 pr_info("use-after-free in strrchr\n");
650 pr_info("use-after-free in strcmp\n");
653 pr_info("use-after-free in strncmp\n");
654 strncmp(ptr
, "2", 1);
656 pr_info("use-after-free in strlen\n");
659 pr_info("use-after-free in strnlen\n");
663 static noinline
void __init
kasan_bitops(void)
666 * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes;
667 * this way we do not actually corrupt other memory.
669 long *bits
= kzalloc(sizeof(*bits
) + 1, GFP_KERNEL
);
674 * Below calls try to access bit within allocated memory; however, the
675 * below accesses are still out-of-bounds, since bitops are defined to
676 * operate on the whole long the bit is in.
678 pr_info("out-of-bounds in set_bit\n");
679 set_bit(BITS_PER_LONG
, bits
);
681 pr_info("out-of-bounds in __set_bit\n");
682 __set_bit(BITS_PER_LONG
, bits
);
684 pr_info("out-of-bounds in clear_bit\n");
685 clear_bit(BITS_PER_LONG
, bits
);
687 pr_info("out-of-bounds in __clear_bit\n");
688 __clear_bit(BITS_PER_LONG
, bits
);
690 pr_info("out-of-bounds in clear_bit_unlock\n");
691 clear_bit_unlock(BITS_PER_LONG
, bits
);
693 pr_info("out-of-bounds in __clear_bit_unlock\n");
694 __clear_bit_unlock(BITS_PER_LONG
, bits
);
696 pr_info("out-of-bounds in change_bit\n");
697 change_bit(BITS_PER_LONG
, bits
);
699 pr_info("out-of-bounds in __change_bit\n");
700 __change_bit(BITS_PER_LONG
, bits
);
703 * Below calls try to access bit beyond allocated memory.
705 pr_info("out-of-bounds in test_and_set_bit\n");
706 test_and_set_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
708 pr_info("out-of-bounds in __test_and_set_bit\n");
709 __test_and_set_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
711 pr_info("out-of-bounds in test_and_set_bit_lock\n");
712 test_and_set_bit_lock(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
714 pr_info("out-of-bounds in test_and_clear_bit\n");
715 test_and_clear_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
717 pr_info("out-of-bounds in __test_and_clear_bit\n");
718 __test_and_clear_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
720 pr_info("out-of-bounds in test_and_change_bit\n");
721 test_and_change_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
723 pr_info("out-of-bounds in __test_and_change_bit\n");
724 __test_and_change_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
726 pr_info("out-of-bounds in test_bit\n");
727 (void)test_bit(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
729 #if defined(clear_bit_unlock_is_negative_byte)
730 pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
731 clear_bit_unlock_is_negative_byte(BITS_PER_LONG
+ BITS_PER_BYTE
, bits
);
736 static noinline
void __init
kmalloc_double_kzfree(void)
741 pr_info("double-free (kzfree)\n");
742 ptr
= kmalloc(size
, GFP_KERNEL
);
744 pr_err("Allocation failed\n");
752 static int __init
kmalloc_tests_init(void)
755 * Temporarily enable multi-shot mode. Otherwise, we'd only get a
756 * report for the first case.
758 bool multishot
= kasan_save_enable_multi_shot();
762 kmalloc_node_oob_right();
764 kmalloc_pagealloc_oob_right();
765 kmalloc_pagealloc_uaf();
766 kmalloc_pagealloc_invalid_free();
768 kmalloc_large_oob_right();
769 kmalloc_oob_krealloc_more();
770 kmalloc_oob_krealloc_less();
772 kmalloc_oob_in_memset();
773 kmalloc_oob_memset_2();
774 kmalloc_oob_memset_4();
775 kmalloc_oob_memset_8();
776 kmalloc_oob_memset_16();
778 kmalloc_uaf_memset();
783 memcg_accounted_kmem_cache();
786 kasan_alloca_oob_left();
787 kasan_alloca_oob_right();
788 ksize_unpoisons_memory();
790 kmem_cache_double_free();
791 kmem_cache_invalid_free();
796 kmalloc_double_kzfree();
798 kasan_restore_multi_shot(multishot
);
803 module_init(kmalloc_tests_init
);
804 MODULE_LICENSE("GPL");