linux/lib/fortify_kunit.c
Linus Torvalds 76d9b92e68 slab updates for 6.11
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Merge tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:
 "The most prominent change this time is the kmem_buckets based
  hardening of kmalloc() allocations from Kees Cook.

  We have also extended the kmalloc() alignment guarantees for
  non-power-of-two sizes in a way that benefits rust.

  The rest are various cleanups and non-critical fixups.

   - Dedicated bucket allocator (Kees Cook)

     This series [1] enhances the probabilistic defense against heap
     spraying/grooming of CONFIG_RANDOM_KMALLOC_CACHES from last year.

     kmalloc() users that are known to be useful for exploits can get
     completely separate set of kmalloc caches that can't be shared with
     other users. The first converted users are alloc_msg() and
     memdup_user().

     The hardening is enabled by CONFIG_SLAB_BUCKETS.

   - Extended kmalloc() alignment guarantees (Vlastimil Babka)

     For years now we have guaranteed natural alignment for power-of-two
     allocations, but nothing was defined for other sizes (in practice,
     we have two such buckets, kmalloc-96 and kmalloc-192).

     To avoid unnecessary padding in the rust layer due to its alignment
     rules, extend the guarantee so that the alignment is at least the
     largest power-of-two divisor of the requested size.

     This fits what rust needs, is a superset of the existing
     power-of-two guarantee, and does not in practice change the layout
     (and thus does not add overhead due to padding) of the kmalloc-96
     and kmalloc-192 caches, unless slab debugging is enabled for them.

   - Cleanups and non-critical fixups (Chengming Zhou, Suren
     Baghdasaryan, Matthew Willcox, Alex Shi, and Vlastimil Babka)

     Various tweaks related to the new alloc profiling code, folio
     conversion, debugging and more leftovers after SLAB"

Link: https://lore.kernel.org/all/20240701190152.it.631-kees@kernel.org/ [1]

* tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/memcg: alignment memcg_data define condition
  mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILING
  mm, slab: move allocation tagging code in the alloc path into a hook
  mm/util: Use dedicated slab buckets for memdup_user()
  ipc, msg: Use dedicated slab buckets for alloc_msg()
  mm/slab: Introduce kmem_buckets_create() and family
  mm/slab: Introduce kvmalloc_buckets_node() that can take kmem_buckets argument
  mm/slab: Plumb kmem_buckets into __do_kmalloc_node()
  mm/slab: Introduce kmem_buckets typedef
  slab, rust: extend kmalloc() alignment guarantees to remove Rust padding
  slab: delete useless RED_INACTIVE and RED_ACTIVE
  slab: don't put freepointer outside of object if only orig_size
  slab: make check_object() more consistent
  mm: Reduce the number of slab->folio casts
  mm, slab: don't wrap internal functions with alloc_hooks()
2024-07-18 15:08:12 -07:00

1097 lines
39 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Runtime test cases for CONFIG_FORTIFY_SOURCE. For additional memcpy()
* testing see FORTIFY_MEM_* tests in LKDTM (drivers/misc/lkdtm/fortify.c).
*
* For corner cases with UBSAN, try testing with:
*
* ./tools/testing/kunit/kunit.py run --arch=x86_64 \
* --kconfig_add CONFIG_FORTIFY_SOURCE=y \
* --kconfig_add CONFIG_UBSAN=y \
* --kconfig_add CONFIG_UBSAN_TRAP=y \
* --kconfig_add CONFIG_UBSAN_BOUNDS=y \
* --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \
* --make_options LLVM=1 fortify
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
/* We don't need to fill dmesg with the fortify WARNs during testing. */
#ifdef DEBUG
# define FORTIFY_REPORT_KUNIT(x...) __fortify_report(x)
# define FORTIFY_WARN_KUNIT(x...) WARN_ONCE(x)
#else
# define FORTIFY_REPORT_KUNIT(x...) do { } while (0)
# define FORTIFY_WARN_KUNIT(x...) do { } while (0)
#endif
/* Redefine fortify_panic() to track failures. */
void fortify_add_kunit_error(int write);
#define fortify_panic(func, write, avail, size, retfail) do { \
FORTIFY_REPORT_KUNIT(FORTIFY_REASON(func, write), avail, size); \
fortify_add_kunit_error(write); \
return (retfail); \
} while (0)
/* Redefine fortify_warn_once() to track memcpy() failures. */
#define fortify_warn_once(chk_func, x...) do { \
bool __result = chk_func; \
FORTIFY_WARN_KUNIT(__result, x); \
if (__result) \
fortify_add_kunit_error(1); \
} while (0)
#include <kunit/device.h>
#include <kunit/test.h>
#include <kunit/test-bug.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
/* Handle being built without CONFIG_FORTIFY_SOURCE */
#ifndef __compiletime_strlen
# define __compiletime_strlen __builtin_strlen
#endif
static struct kunit_resource read_resource;
static struct kunit_resource write_resource;
static int fortify_read_overflows;
static int fortify_write_overflows;
static const char array_of_10[] = "this is 10";
static const char *ptr_of_11 = "this is 11!";
static char array_unknown[] = "compiler thinks I might change";
void fortify_add_kunit_error(int write)
{
struct kunit_resource *resource;
struct kunit *current_test;
current_test = kunit_get_current_test();
if (!current_test)
return;
resource = kunit_find_named_resource(current_test,
write ? "fortify_write_overflows"
: "fortify_read_overflows");
if (!resource)
return;
(*(int *)resource->data)++;
kunit_put_resource(resource);
}
static void fortify_test_known_sizes(struct kunit *test)
{
KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11);
KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX);
/* Externally defined and dynamically sized string pointer: */
KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX);
}
/* This is volatile so the optimizer can't perform DCE below. */
static volatile int pick;
/* Not inline to keep optimizer from figuring out which string we want. */
static noinline size_t want_minus_one(int pick)
{
const char *str;
switch (pick) {
case 1:
str = "4444";
break;
case 2:
str = "333";
break;
default:
str = "1";
break;
}
return __compiletime_strlen(str);
}
static void fortify_test_control_flow_split(struct kunit *test)
{
KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
}
#define KUNIT_EXPECT_BOS(test, p, expected, name) \
KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \
expected, \
"__alloc_size() not working with __bos on " name "\n")
#if !__has_builtin(__builtin_dynamic_object_size)
#define KUNIT_EXPECT_BDOS(test, p, expected, name) \
/* Silence "unused variable 'expected'" warning. */ \
KUNIT_EXPECT_EQ(test, expected, expected)
#else
#define KUNIT_EXPECT_BDOS(test, p, expected, name) \
KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \
expected, \
"__alloc_size() not working with __bdos on " name "\n")
#endif
/* If the execpted size is a constant value, __bos can see it. */
#define check_const(_expected, alloc, free) do { \
size_t expected = (_expected); \
void *p = alloc; \
KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \
KUNIT_EXPECT_BOS(test, p, expected, #alloc); \
KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \
free; \
} while (0)
/* If the execpted size is NOT a constant value, __bos CANNOT see it. */
#define check_dynamic(_expected, alloc, free) do { \
size_t expected = (_expected); \
void *p = alloc; \
KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \
KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \
KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \
free; \
} while (0)
/* Assortment of constant-value kinda-edge cases. */
#define CONST_TEST_BODY(TEST_alloc) do { \
/* Special-case vmalloc()-family to skip 0-sized allocs. */ \
if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \
TEST_alloc(check_const, 0, 0); \
TEST_alloc(check_const, 1, 1); \
TEST_alloc(check_const, 128, 128); \
TEST_alloc(check_const, 1023, 1023); \
TEST_alloc(check_const, 1025, 1025); \
TEST_alloc(check_const, 4096, 4096); \
TEST_alloc(check_const, 4097, 4097); \
} while (0)
static volatile size_t zero_size;
static volatile size_t unknown_size = 50;
#if !__has_builtin(__builtin_dynamic_object_size)
#define DYNAMIC_TEST_BODY(TEST_alloc) \
kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n")
#else
#define DYNAMIC_TEST_BODY(TEST_alloc) do { \
size_t size = unknown_size; \
\
/* \
* Expected size is "size" in each test, before it is then \
* internally incremented in each test. Requires we disable \
* -Wunsequenced. \
*/ \
TEST_alloc(check_dynamic, size, size++); \
/* Make sure incrementing actually happened. */ \
KUNIT_EXPECT_NE(test, size, unknown_size); \
} while (0)
#endif
#define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \
static void fortify_test_alloc_size_##allocator##_const(struct kunit *test) \
{ \
CONST_TEST_BODY(TEST_##allocator); \
} \
static void fortify_test_alloc_size_##allocator##_dynamic(struct kunit *test) \
{ \
DYNAMIC_TEST_BODY(TEST_##allocator); \
}
#define TEST_kmalloc(checker, expected_size, alloc_size) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
void *orig; \
size_t len; \
\
checker(expected_size, kmalloc(alloc_size, gfp), \
kfree(p)); \
checker(expected_size, \
kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, kzalloc(alloc_size, gfp), \
kfree(p)); \
checker(expected_size, \
kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, kcalloc(1, alloc_size, gfp), \
kfree(p)); \
checker(expected_size, kcalloc(alloc_size, 1, gfp), \
kfree(p)); \
checker(expected_size, \
kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, \
kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, kmalloc_array(1, alloc_size, gfp), \
kfree(p)); \
checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \
kfree(p)); \
checker(expected_size, \
kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, \
kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
kfree(p)); \
\
orig = kmalloc(alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
krealloc(orig, (alloc_size) * 2, gfp), \
kfree(p)); \
orig = kmalloc(alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
krealloc_array(orig, 1, (alloc_size) * 2, gfp), \
kfree(p)); \
orig = kmalloc(alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
krealloc_array(orig, (alloc_size) * 2, 1, gfp), \
kfree(p)); \
\
len = 11; \
/* Using memdup() with fixed size, so force unknown length. */ \
if (!__builtin_constant_p(expected_size)) \
len += zero_size; \
checker(len, kmemdup("hello there", len, gfp), kfree(p)); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc)
/* Sizes are in pages, not bytes. */
#define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
checker((expected_pages) * PAGE_SIZE, \
vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
__vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc)
/* Sizes are in pages (and open-coded for side-effects), not bytes. */
#define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
size_t prev_size; \
void *orig; \
\
checker((expected_pages) * PAGE_SIZE, \
kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \
kvfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \
kvfree(p)); \
\
prev_size = (expected_pages) * PAGE_SIZE; \
orig = kvmalloc(prev_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker(((expected_pages) * PAGE_SIZE) * 2, \
kvrealloc(orig, prev_size, \
((alloc_pages) * PAGE_SIZE) * 2, gfp), \
kvfree(p)); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc)
#define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
const char dev_name[] = "fortify-test"; \
struct device *dev; \
void *orig; \
size_t len; \
\
/* Create dummy device for devm_kmalloc()-family tests. */ \
dev = kunit_device_register(test, dev_name); \
KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \
"Cannot register test device\n"); \
\
checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kmalloc_array(dev, 1, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kmalloc_array(dev, alloc_size, 1, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kcalloc(dev, 1, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kcalloc(dev, alloc_size, 1, gfp), \
devm_kfree(dev, p)); \
\
orig = devm_kmalloc(dev, alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \
devm_kfree(dev, p)); \
\
len = 4; \
/* Using memdup() with fixed size, so force unknown length. */ \
if (!__builtin_constant_p(expected_size)) \
len += zero_size; \
checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \
devm_kfree(dev, p)); \
\
kunit_device_unregister(test, dev); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc)
static const char * const test_strs[] = {
"",
"Hello there",
"A longer string, just for variety",
};
#define TEST_realloc(checker) do { \
gfp_t gfp = GFP_KERNEL; \
size_t len; \
int i; \
\
for (i = 0; i < ARRAY_SIZE(test_strs); i++) { \
len = strlen(test_strs[i]); \
KUNIT_EXPECT_EQ(test, __builtin_constant_p(len), 0); \
checker(len, kmemdup_array(test_strs[i], 1, len, gfp), \
kfree(p)); \
checker(len, kmemdup(test_strs[i], len, gfp), \
kfree(p)); \
} \
} while (0)
static void fortify_test_realloc_size(struct kunit *test)
{
TEST_realloc(check_dynamic);
}
/*
* We can't have an array at the end of a structure or else
* builds without -fstrict-flex-arrays=3 will report them as
* being an unknown length. Additionally, add bytes before
* and after the string to catch over/underflows if tests
* fail.
*/
struct fortify_padding {
unsigned long bytes_before;
char buf[32];
unsigned long bytes_after;
};
/* Force compiler into not being able to resolve size at compile-time. */
static volatile int unconst;
static void fortify_test_strlen(struct kunit *test)
{
struct fortify_padding pad = { };
int i, end = sizeof(pad.buf) - 1;
/* Fill 31 bytes with valid characters. */
for (i = 0; i < sizeof(pad.buf) - 1; i++)
pad.buf[i] = i + '0';
/* Trailing bytes are still %NUL. */
KUNIT_EXPECT_EQ(test, pad.buf[end], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* String is terminated, so strlen() is valid. */
KUNIT_EXPECT_EQ(test, strlen(pad.buf), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Make string unterminated, and recount. */
pad.buf[end] = 'A';
end = sizeof(pad.buf);
KUNIT_EXPECT_EQ(test, strlen(pad.buf), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
}
static void fortify_test_strnlen(struct kunit *test)
{
struct fortify_padding pad = { };
int i, end = sizeof(pad.buf) - 1;
/* Fill 31 bytes with valid characters. */
for (i = 0; i < sizeof(pad.buf) - 1; i++)
pad.buf[i] = i + '0';
/* Trailing bytes are still %NUL. */
KUNIT_EXPECT_EQ(test, pad.buf[end], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* String is terminated, so strnlen() is valid. */
KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf)), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* A truncated strnlen() will be safe, too. */
KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf) / 2),
sizeof(pad.buf) / 2);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Make string unterminated, and recount. */
pad.buf[end] = 'A';
end = sizeof(pad.buf);
/* Reading beyond with strncpy() will fail. */
KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 1), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 2), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
/* Early-truncated is safe still, though. */
KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
end = sizeof(pad.buf) / 2;
KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
}
static void fortify_test_strcpy(struct kunit *test)
{
struct fortify_padding pad = { };
char src[sizeof(pad.buf) + 1] = { };
int i;
/* Fill 31 bytes with valid characters. */
for (i = 0; i < sizeof(src) - 2; i++)
src[i] = i + '0';
/* Destination is %NUL-filled to start with. */
KUNIT_EXPECT_EQ(test, pad.bytes_before, 0);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Legitimate strcpy() 1 less than of max size. */
KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src)
== pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Only last byte should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
src[sizeof(src) - 2] = 'A';
/* But now we trip the overflow checking. */
KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src)
== pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);
/* Trailing %NUL -- thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* And we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
src[sizeof(src) - 1] = 'A';
/* And for sure now, two bytes past. */
KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src)
== pad.buf);
/*
* Which trips both the strlen() on the unterminated src,
* and the resulting copy attempt.
*/
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
/* Trailing %NUL -- thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* And we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
}
static void fortify_test_strncpy(struct kunit *test)
{
struct fortify_padding pad = { };
char src[] = "Copy me fully into a small buffer and I will overflow!";
/* Destination is %NUL-filled to start with. */
KUNIT_EXPECT_EQ(test, pad.bytes_before, 0);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Legitimate strncpy() 1 less than of max size. */
KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src,
sizeof(pad.buf) + unconst - 1)
== pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Only last byte should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* Legitimate (though unterminated) max-size strncpy. */
KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src,
sizeof(pad.buf) + unconst)
== pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* No trailing %NUL -- thanks strncpy API. */
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* But we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Now verify that FORTIFY is working... */
KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src,
sizeof(pad.buf) + unconst + 1)
== pad.buf);
/* Should catch the overflow. */
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* And we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* And further... */
KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src,
sizeof(pad.buf) + unconst + 2)
== pad.buf);
/* Should catch the overflow. */
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* And we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
}
static void fortify_test_strscpy(struct kunit *test)
{
struct fortify_padding pad = { };
char src[] = "Copy me fully into a small buffer and I will overflow!";
/* Destination is %NUL-filled to start with. */
KUNIT_EXPECT_EQ(test, pad.bytes_before, 0);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Legitimate strscpy() 1 less than of max size. */
KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src,
sizeof(pad.buf) + unconst - 1),
-E2BIG);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Keeping space for %NUL, last two bytes should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* Legitimate max-size strscpy. */
KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src,
sizeof(pad.buf) + unconst),
-E2BIG);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* A trailing %NUL will exist. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* Now verify that FORTIFY is working... */
KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src,
sizeof(pad.buf) + unconst + 1),
-E2BIG);
/* Should catch the overflow. */
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* And we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* And much further... */
KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src,
sizeof(src) * 2 + unconst),
-E2BIG);
/* Should catch the overflow. */
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
/* And we will not have gone beyond. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
}
static void fortify_test_strcat(struct kunit *test)
{
struct fortify_padding pad = { };
char src[sizeof(pad.buf) / 2] = { };
char one[] = "A";
char two[] = "BC";
int i;
/* Fill 15 bytes with valid characters. */
for (i = 0; i < sizeof(src) - 1; i++)
src[i] = i + 'A';
/* Destination is %NUL-filled to start with. */
KUNIT_EXPECT_EQ(test, pad.bytes_before, 0);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Legitimate strcat() using less than half max size. */
KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Legitimate strcat() now 2 bytes shy of end. */
KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Last two bytes should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* Add one more character to the end. */
KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Last byte should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* And this one char will overflow. */
KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);
/* Last byte should be %NUL thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* And adding two will overflow more. */
KUNIT_ASSERT_TRUE(test, strcat(pad.buf, two) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
/* Last byte should be %NUL thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
}
static void fortify_test_strncat(struct kunit *test)
{
struct fortify_padding pad = { };
char src[sizeof(pad.buf)] = { };
int i, partial;
/* Fill 31 bytes with valid characters. */
partial = sizeof(src) / 2 - 1;
for (i = 0; i < partial; i++)
src[i] = i + 'A';
/* Destination is %NUL-filled to start with. */
KUNIT_EXPECT_EQ(test, pad.bytes_before, 0);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Legitimate strncat() using less than half max size. */
KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Legitimate strncat() now 2 bytes shy of end. */
KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Last two bytes should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* Add one more character to the end. */
KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Last byte should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* And this one char will overflow. */
KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);
/* Last byte should be %NUL thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* And adding two will overflow more. */
KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 2) == pad.buf);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
/* Last byte should be %NUL thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Force an unterminated destination, and overflow. */
pad.buf[sizeof(pad.buf) - 1] = 'A';
KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf);
/* This will have tripped both strlen() and strcat(). */
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3);
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* But we should not go beyond the end. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
}
static void fortify_test_strlcat(struct kunit *test)
{
struct fortify_padding pad = { };
char src[sizeof(pad.buf)] = { };
int i, partial;
int len = sizeof(pad.buf) + unconst;
/* Fill 15 bytes with valid characters. */
partial = sizeof(src) / 2 - 1;
for (i = 0; i < partial; i++)
src[i] = i + 'A';
/* Destination is %NUL-filled to start with. */
KUNIT_EXPECT_EQ(test, pad.bytes_before, 0);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Legitimate strlcat() using less than half max size. */
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Legitimate strlcat() now 2 bytes shy of end. */
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial * 2);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Last two bytes should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* Add one more character to the end. */
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "Q", len), partial * 2 + 1);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);
/* Last byte should be %NUL */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* And this one char will overflow. */
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "V", len * 2), len);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);
/* Last byte should be %NUL thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* And adding two will overflow more. */
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "QQ", len * 2), len + 1);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
/* Last byte should be %NUL thanks to FORTIFY. */
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Force an unterminated destination, and overflow. */
pad.buf[sizeof(pad.buf) - 1] = 'A';
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "TT", len * 2), len + 2);
/* This will have tripped both strlen() and strlcat(). */
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0');
KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0');
/* But we should not go beyond the end. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
/* Force an unterminated source, and overflow. */
memset(src, 'B', sizeof(src));
pad.buf[sizeof(pad.buf) - 1] = '\0';
KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len * 3), len - 1 + sizeof(src));
/* This will have tripped both strlen() and strlcat(). */
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3);
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3);
KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0');
/* But we should not go beyond the end. */
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
}
/* Check for 0-sized arrays... */
struct fortify_zero_sized {
unsigned long bytes_before;
char buf[0];
unsigned long bytes_after;
};
#define __fortify_test(memfunc) \
static void fortify_test_##memfunc(struct kunit *test) \
{ \
struct fortify_zero_sized zero = { }; \
struct fortify_padding pad = { }; \
char srcA[sizeof(pad.buf) + 2]; \
char srcB[sizeof(pad.buf) + 2]; \
size_t len = sizeof(pad.buf) + unconst; \
\
memset(srcA, 'A', sizeof(srcA)); \
KUNIT_ASSERT_EQ(test, srcA[0], 'A'); \
memset(srcB, 'B', sizeof(srcB)); \
KUNIT_ASSERT_EQ(test, srcB[0], 'B'); \
\
memfunc(pad.buf, srcA, 0 + unconst); \
KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \
memfunc(pad.buf + 1, srcB, 1 + unconst); \
KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \
KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \
KUNIT_EXPECT_EQ(test, pad.buf[2], '\0'); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \
memfunc(pad.buf, srcA, 1 + unconst); \
KUNIT_EXPECT_EQ(test, pad.buf[0], 'A'); \
KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \
memfunc(pad.buf, srcA, len - 1); \
KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \
KUNIT_EXPECT_EQ(test, pad.buf[len - 1], '\0'); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \
memfunc(pad.buf, srcA, len); \
KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \
KUNIT_EXPECT_EQ(test, pad.buf[len - 1], 'A'); \
KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \
memfunc(pad.buf, srcA, len + 1); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \
memfunc(pad.buf + 1, srcB, len); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); \
\
/* Reset error counter. */ \
fortify_write_overflows = 0; \
/* Copy nothing into nothing: no errors. */ \
memfunc(zero.buf, srcB, 0 + unconst); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \
memfunc(zero.buf, srcB, 1 + unconst); \
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \
KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \
}
__fortify_test(memcpy)
__fortify_test(memmove)
static void fortify_test_memscan(struct kunit *test)
{
char haystack[] = "Where oh where is my memory range?";
char *mem = haystack + strlen("Where oh where is ");
char needle = 'm';
size_t len = sizeof(haystack) + unconst;
KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len),
mem);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Catch too-large range. */
KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len + 1),
NULL);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len * 2),
NULL);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
}
static void fortify_test_memchr(struct kunit *test)
{
char haystack[] = "Where oh where is my memory range?";
char *mem = haystack + strlen("Where oh where is ");
char needle = 'm';
size_t len = sizeof(haystack) + unconst;
KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len),
mem);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Catch too-large range. */
KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len + 1),
NULL);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len * 2),
NULL);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
}
static void fortify_test_memchr_inv(struct kunit *test)
{
char haystack[] = "Where oh where is my memory range?";
char *mem = haystack + 1;
char needle = 'W';
size_t len = sizeof(haystack) + unconst;
/* Normal search is okay. */
KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len),
mem);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Catch too-large range. */
KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len + 1),
NULL);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len * 2),
NULL);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
}
static void fortify_test_memcmp(struct kunit *test)
{
char one[] = "My mind is going ...";
char two[] = "My mind is going ... I can feel it.";
size_t one_len = sizeof(one) + unconst - 1;
size_t two_len = sizeof(two) + unconst - 1;
/* We match the first string (ignoring the %NUL). */
KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len), 0);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Still in bounds, but no longer matching. */
KUNIT_ASSERT_LT(test, memcmp(one, two, one_len + 1), 0);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
/* Catch too-large ranges. */
KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len + 2), INT_MIN);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
KUNIT_ASSERT_EQ(test, memcmp(two, one, two_len + 2), INT_MIN);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
}
static void fortify_test_kmemdup(struct kunit *test)
{
char src[] = "I got Doom running on it!";
char *copy;
size_t len = sizeof(src) + unconst;
/* Copy is within bounds. */
copy = kmemdup(src, len, GFP_KERNEL);
KUNIT_EXPECT_NOT_NULL(test, copy);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
kfree(copy);
/* Without %NUL. */
copy = kmemdup(src, len - 1, GFP_KERNEL);
KUNIT_EXPECT_NOT_NULL(test, copy);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
kfree(copy);
/* Tiny bounds. */
copy = kmemdup(src, 1, GFP_KERNEL);
KUNIT_EXPECT_NOT_NULL(test, copy);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);
kfree(copy);
/* Out of bounds by 1 byte. */
copy = kmemdup(src, len + 1, GFP_KERNEL);
KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
kfree(copy);
/* Way out of bounds. */
copy = kmemdup(src, len * 2, GFP_KERNEL);
KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
kfree(copy);
/* Starting offset causing out of bounds. */
copy = kmemdup(src + 1, len, GFP_KERNEL);
KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3);
kfree(copy);
}
static int fortify_test_init(struct kunit *test)
{
if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE))
kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y");
fortify_read_overflows = 0;
kunit_add_named_resource(test, NULL, NULL, &read_resource,
"fortify_read_overflows",
&fortify_read_overflows);
fortify_write_overflows = 0;
kunit_add_named_resource(test, NULL, NULL, &write_resource,
"fortify_write_overflows",
&fortify_write_overflows);
return 0;
}
static struct kunit_case fortify_test_cases[] = {
KUNIT_CASE(fortify_test_known_sizes),
KUNIT_CASE(fortify_test_control_flow_split),
KUNIT_CASE(fortify_test_alloc_size_kmalloc_const),
KUNIT_CASE(fortify_test_alloc_size_kmalloc_dynamic),
KUNIT_CASE(fortify_test_alloc_size_vmalloc_const),
KUNIT_CASE(fortify_test_alloc_size_vmalloc_dynamic),
KUNIT_CASE(fortify_test_alloc_size_kvmalloc_const),
KUNIT_CASE(fortify_test_alloc_size_kvmalloc_dynamic),
KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_const),
KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_dynamic),
KUNIT_CASE(fortify_test_realloc_size),
KUNIT_CASE(fortify_test_strlen),
KUNIT_CASE(fortify_test_strnlen),
KUNIT_CASE(fortify_test_strcpy),
KUNIT_CASE(fortify_test_strncpy),
KUNIT_CASE(fortify_test_strscpy),
KUNIT_CASE(fortify_test_strcat),
KUNIT_CASE(fortify_test_strncat),
KUNIT_CASE(fortify_test_strlcat),
/* skip memset: performs bounds checking on whole structs */
KUNIT_CASE(fortify_test_memcpy),
KUNIT_CASE(fortify_test_memmove),
KUNIT_CASE(fortify_test_memscan),
KUNIT_CASE(fortify_test_memchr),
KUNIT_CASE(fortify_test_memchr_inv),
KUNIT_CASE(fortify_test_memcmp),
KUNIT_CASE(fortify_test_kmemdup),
{}
};
static struct kunit_suite fortify_test_suite = {
.name = "fortify",
.init = fortify_test_init,
.test_cases = fortify_test_cases,
};
kunit_test_suite(fortify_test_suite);
MODULE_LICENSE("GPL");