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ubsan: expand tests and reporting 

Expand the UBSAN tests to include some additional UB cases.  Notably the
out-of-bounds enum loading appears not to work.  Also include per-test
reporting, including the relevant CONFIG_UBSAN...  Kconfigs.

Link: https://lkml.kernel.org/r/20201203004437.389959-8-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kees Cook 2020-12-15 20:46:43 -08:00 committed by Linus Torvalds
parent c637693b20
commit 4a26f49b7b
1 changed files with 66 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
lib/test_ubsan.c
View File

@ -5,32 +5,54 @@
typedef void(*test_ubsan_fp)(void);
#define UBSAN_TEST(config, ...) do { \
pr_info("%s " __VA_ARGS__ "%s(%s=%s)\n", __func__, \
sizeof(" " __VA_ARGS__) > 2 ? " " : "", \
#config, IS_ENABLED(config) ? "y" : "n"); \
} while (0)
static void test_ubsan_add_overflow(void)
{
volatile int val = INT_MAX;
volatile unsigned int uval = UINT_MAX;
UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW);
val += 2;
UBSAN_TEST(CONFIG_UBSAN_UNSIGNED_OVERFLOW);
uval += 2;
}
static void test_ubsan_sub_overflow(void)
{
volatile int val = INT_MIN;
volatile unsigned int uval = 0;
volatile int val2 = 2;
UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW);
val -= val2;
UBSAN_TEST(CONFIG_UBSAN_UNSIGNED_OVERFLOW);
uval -= val2;
}
static void test_ubsan_mul_overflow(void)
{
volatile int val = INT_MAX / 2;
volatile unsigned int uval = UINT_MAX / 2;
UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW);
val *= 3;
UBSAN_TEST(CONFIG_UBSAN_UNSIGNED_OVERFLOW);
uval *= 3;
}
static void test_ubsan_negate_overflow(void)
{
volatile int val = INT_MIN;
UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW);
val = -val;
}
@ -39,37 +61,67 @@ static void test_ubsan_divrem_overflow(void)
volatile int val = 16;
volatile int val2 = 0;
UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO);
val /= val2;
}
static void test_ubsan_shift_out_of_bounds(void)
{
volatile int val = -1;
int val2 = 10;
volatile int neg = -1, wrap = 4;
int val1 = 10;
int val2 = INT_MAX;
val2 <<= val;
UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
val1 <<= neg;
UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow");
val2 <<= wrap;
}
static void test_ubsan_out_of_bounds(void)
{
volatile int i = 4, j = 5;
volatile int i = 4, j = 5, k = -1;
volatile char above[4] = { }; /* Protect surrounding memory. */
volatile int arr[4];
volatile char below[4] = { }; /* Protect surrounding memory. */
above[0] = below[0];
UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above");
arr[j] = i;
UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below");
arr[k] = i;
}
enum ubsan_test_enum {
UBSAN_TEST_ZERO = 0,
UBSAN_TEST_ONE,
UBSAN_TEST_MAX,
};
static void test_ubsan_load_invalid_value(void)
{
volatile char *dst, *src;
bool val, val2, *ptr;
char c = 4;
enum ubsan_test_enum eval, eval2, *eptr;
unsigned char c = 0xff;
UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool");
dst = (char *)&val;
src = &c;
*dst = *src;
ptr = &val2;
val2 = val;
UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum");
dst = (char *)&eval;
src = &c;
*dst = *src;
eptr = &eval2;
eval2 = eval;
}
static void test_ubsan_null_ptr_deref(void)
@ -77,6 +129,7 @@ static void test_ubsan_null_ptr_deref(void)
volatile int *ptr = NULL;
int val;
UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE);
val = *ptr;
}
@ -85,6 +138,7 @@ static void test_ubsan_misaligned_access(void)
volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
volatile int *ptr, val = 6;
UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT);
ptr = (int *)(arr + 1);
*ptr = val;
}
@ -95,6 +149,7 @@ static void test_ubsan_object_size_mismatch(void)
volatile int val __aligned(8) = 4;
volatile long long *ptr, val2;
UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE);
ptr = (long long *)&val;
val2 = *ptr;
}
@ -104,15 +159,19 @@ static const test_ubsan_fp test_ubsan_array[] = {
test_ubsan_sub_overflow,
test_ubsan_mul_overflow,
test_ubsan_negate_overflow,
test_ubsan_divrem_overflow,
test_ubsan_shift_out_of_bounds,
test_ubsan_out_of_bounds,
test_ubsan_load_invalid_value,
//test_ubsan_null_ptr_deref, /* exclude it because there is a crash */
test_ubsan_misaligned_access,
test_ubsan_object_size_mismatch,
};
/* Excluded because they Oops the module. */
static const test_ubsan_fp skip_ubsan_array[] = {
test_ubsan_divrem_overflow,
test_ubsan_null_ptr_deref,
};
static int __init test_ubsan_init(void)
{
unsigned int i;
@ -120,7 +179,6 @@ static int __init test_ubsan_init(void)
for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
test_ubsan_array[i]();
(void)test_ubsan_null_ptr_deref; /* to avoid unsed-function warning */
return 0;
}
module_init(test_ubsan_init);