The patch titled
Subject: ubsan: expand tests and reporting
has been added to the -mm tree. Its filename is
ubsan-expand-tests-and-reporting.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/ubsan-expand-tests-and-reporting.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/ubsan-expand-tests-and-reporting.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: George Popescu <georgepope@xxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Michal Marek <michal.lkml@xxxxxxxxxxx>
Cc: Nathan Chancellor <natechancellor@xxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_ubsan.c | 74 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 66 insertions(+), 8 deletions(-)
--- a/lib/test_ubsan.c~ubsan-expand-tests-and-reporting
+++ a/lib/test_ubsan.c
@@ -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(v
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;
+
+ UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent");
+ val1 <<= neg;
- val2 <<= val;
+ 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(vo
volatile int *ptr = NULL;
int val;
+ UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE);
val = *ptr;
}
@@ -85,6 +138,7 @@ static void test_ubsan_misaligned_access
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_misma
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_ar
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);
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
ubsan-remove-redundant-wno-maybe-uninitialized.patch
ubsan-move-cc-option-tests-into-kconfig.patch
ubsan-disable-object-size-sanitizer-under-gcc.patch
ubsan-disable-ubsan_trap-for-allconfig.patch
ubsan-enable-for-allconfig-builds.patch
ubsan-remove-ubsan_misc-in-favor-of-individual-options.patch
ubsan-expand-tests-and-reporting.patch
