From 455a35a6cdb6f53fe9294e23301eb056f2908bd9 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Tue, 8 May 2018 00:36:28 +0200 Subject: lib: add runtime test of check_*_overflow functions This adds a small module for testing that the check_*_overflow functions work as expected, whether implemented in C or using gcc builtins. Example output: test_overflow: u8 : 18 tests test_overflow: s8 : 19 tests test_overflow: u16: 17 tests test_overflow: s16: 17 tests test_overflow: u32: 17 tests test_overflow: s32: 17 tests test_overflow: u64: 17 tests test_overflow: s64: 21 tests Signed-off-by: Rasmus Villemoes [kees: add output to commit log, drop u64 tests on 32-bit] Signed-off-by: Kees Cook --- lib/test_overflow.c | 287 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 287 insertions(+) create mode 100644 lib/test_overflow.c (limited to 'lib/test_overflow.c') diff --git a/lib/test_overflow.c b/lib/test_overflow.c new file mode 100644 index 000000000000..af01e46500be --- /dev/null +++ b/lib/test_overflow.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Test cases for arithmetic overflow checks. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +#define DEFINE_TEST_ARRAY(t) \ + static const struct test_ ## t { \ + t a, b; \ + t sum, diff, prod; \ + bool s_of, d_of, p_of; \ + } t ## _tests[] __initconst + +DEFINE_TEST_ARRAY(u8) = { + {0, 0, 0, 0, 0, false, false, false}, + {1, 1, 2, 0, 1, false, false, false}, + {0, 1, 1, U8_MAX, 0, false, true, false}, + {1, 0, 1, 1, 0, false, false, false}, + {0, U8_MAX, U8_MAX, 1, 0, false, true, false}, + {U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false}, + {1, U8_MAX, 0, 2, U8_MAX, true, true, false}, + {U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false}, + {U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true}, + + {U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true}, + {U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true}, + + {1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false}, + {1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true}, + {1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false}, + {1U << 7, 1U << 7, 0, 0, 0, true, false, true}, + + {48, 32, 80, 16, 0, false, false, true}, + {128, 128, 0, 0, 0, true, false, true}, + {123, 234, 101, 145, 110, true, true, true}, +}; +DEFINE_TEST_ARRAY(u16) = { + {0, 0, 0, 0, 0, false, false, false}, + {1, 1, 2, 0, 1, false, false, false}, + {0, 1, 1, U16_MAX, 0, false, true, false}, + {1, 0, 1, 1, 0, false, false, false}, + {0, U16_MAX, U16_MAX, 1, 0, false, true, false}, + {U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false}, + {1, U16_MAX, 0, 2, U16_MAX, true, true, false}, + {U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false}, + {U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true}, + + {U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true}, + {U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true}, + + {1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false}, + {1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true}, + {1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false}, + {1U << 15, 1U << 15, 0, 0, 0, true, false, true}, + + {123, 234, 357, 65425, 28782, false, true, false}, + {1234, 2345, 3579, 64425, 10146, false, true, true}, +}; +DEFINE_TEST_ARRAY(u32) = { + {0, 0, 0, 0, 0, false, false, false}, + {1, 1, 2, 0, 1, false, false, false}, + {0, 1, 1, U32_MAX, 0, false, true, false}, + {1, 0, 1, 1, 0, false, false, false}, + {0, U32_MAX, U32_MAX, 1, 0, false, true, false}, + {U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false}, + {1, U32_MAX, 0, 2, U32_MAX, true, true, false}, + {U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false}, + {U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true}, + + {U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true}, + {U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true}, + + {1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false}, + {1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true}, + {1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false}, + {1U << 31, 1U << 31, 0, 0, 0, true, false, true}, + + {-2U, 1U, -1U, -3U, -2U, false, false, false}, + {-4U, 5U, 1U, -9U, -20U, true, false, true}, +}; + +DEFINE_TEST_ARRAY(u64) = { + {0, 0, 0, 0, 0, false, false, false}, + {1, 1, 2, 0, 1, false, false, false}, + {0, 1, 1, U64_MAX, 0, false, true, false}, + {1, 0, 1, 1, 0, false, false, false}, + {0, U64_MAX, U64_MAX, 1, 0, false, true, false}, + {U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false}, + {1, U64_MAX, 0, 2, U64_MAX, true, true, false}, + {U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false}, + {U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true}, + + {U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true}, + {U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true}, + + {1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false}, + {1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true}, + {1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false}, + {1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true}, + {1000000000ULL /* 10^9 */, 10000000000ULL /* 10^10 */, + 11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL, + false, true, false}, + {-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true}, +}; + +DEFINE_TEST_ARRAY(s8) = { + {0, 0, 0, 0, 0, false, false, false}, + + {0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false}, + {S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false}, + {0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false}, + {S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false}, + + {-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true}, + {S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true}, + {-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false}, + {S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false}, + {-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false}, + {-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false}, + + {1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false}, + {S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false}, + {1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false}, + {S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false}, + + {S8_MIN, S8_MIN, 0, 0, 0, true, false, true}, + {S8_MAX, S8_MAX, -2, 0, 1, true, false, true}, + + {-4, -32, -36, 28, -128, false, false, true}, + {-4, 32, 28, -36, -128, false, false, false}, +}; + +DEFINE_TEST_ARRAY(s16) = { + {0, 0, 0, 0, 0, false, false, false}, + + {0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false}, + {S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false}, + {0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false}, + {S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false}, + + {-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true}, + {S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true}, + {-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false}, + {S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false}, + {-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false}, + {-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false}, + + {1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false}, + {S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false}, + {1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false}, + {S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false}, + + {S16_MIN, S16_MIN, 0, 0, 0, true, false, true}, + {S16_MAX, S16_MAX, -2, 0, 1, true, false, true}, +}; +DEFINE_TEST_ARRAY(s32) = { + {0, 0, 0, 0, 0, false, false, false}, + + {0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false}, + {S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false}, + {0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false}, + {S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false}, + + {-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true}, + {S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true}, + {-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false}, + {S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false}, + {-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false}, + {-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false}, + + {1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false}, + {S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false}, + {1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false}, + {S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false}, + + {S32_MIN, S32_MIN, 0, 0, 0, true, false, true}, + {S32_MAX, S32_MAX, -2, 0, 1, true, false, true}, +}; +DEFINE_TEST_ARRAY(s64) = { + {0, 0, 0, 0, 0, false, false, false}, + + {0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false}, + {S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false}, + {0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false}, + {S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false}, + + {-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true}, + {S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true}, + {-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false}, + {S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false}, + {-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false}, + {-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false}, + + {1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false}, + {S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false}, + {1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false}, + {S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false}, + + {S64_MIN, S64_MIN, 0, 0, 0, true, false, true}, + {S64_MAX, S64_MAX, -2, 0, 1, true, false, true}, + + {-1, -1, -2, 0, 1, false, false, false}, + {-1, -128, -129, 127, 128, false, false, false}, + {-128, -1, -129, -127, 128, false, false, false}, + {0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false}, +}; + +#define DEFINE_TEST_FUNC(t, fmt) \ +static void __init do_test_ ## t(const struct test_ ## t *p) \ +{ \ + t r; \ + bool of; \ + \ + of = check_add_overflow(p->a, p->b, &r); \ + if (of != p->s_of) \ + pr_warn("expected "fmt" + "fmt" to%s overflow (type %s)\n", \ + p->a, p->b, p->s_of ? "" : " not", #t); \ + if (r != p->sum) \ + pr_warn("expected "fmt" + "fmt" == "fmt", got "fmt" (type %s)\n", \ + p->a, p->b, p->sum, r, #t); \ + \ + of = check_sub_overflow(p->a, p->b, &r); \ + if (of != p->d_of) \ + pr_warn("expected "fmt" - "fmt" to%s overflow (type %s)\n", \ + p->a, p->b, p->s_of ? "" : " not", #t); \ + if (r != p->diff) \ + pr_warn("expected "fmt" - "fmt" == "fmt", got "fmt" (type %s)\n", \ + p->a, p->b, p->diff, r, #t); \ + \ + of = check_mul_overflow(p->a, p->b, &r); \ + if (of != p->p_of) \ + pr_warn("expected "fmt" * "fmt" to%s overflow (type %s)\n", \ + p->a, p->b, p->p_of ? "" : " not", #t); \ + if (r != p->prod) \ + pr_warn("expected "fmt" * "fmt" == "fmt", got "fmt" (type %s)\n", \ + p->a, p->b, p->prod, r, #t); \ +} \ + \ +static void __init test_ ## t ## _overflow(void) { \ + unsigned i; \ + \ + pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests)); \ + for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i) \ + do_test_ ## t(&t ## _tests[i]); \ +} + +DEFINE_TEST_FUNC(u8, "%d"); +DEFINE_TEST_FUNC(s8, "%d"); +DEFINE_TEST_FUNC(u16, "%d"); +DEFINE_TEST_FUNC(s16, "%d"); +DEFINE_TEST_FUNC(u32, "%u"); +DEFINE_TEST_FUNC(s32, "%d"); +#if BITS_PER_LONG == 64 +DEFINE_TEST_FUNC(u64, "%llu"); +DEFINE_TEST_FUNC(s64, "%lld"); +#endif + +static int __init test_overflow(void) +{ + test_u8_overflow(); + test_s8_overflow(); + test_u16_overflow(); + test_s16_overflow(); + test_u32_overflow(); + test_s32_overflow(); +#if BITS_PER_LONG == 64 + test_u64_overflow(); + test_s64_overflow(); +#endif + + pr_info("done\n"); + + return 0; +} + +static void __exit test_module_exit(void) +{ } + +module_init(test_overflow); +module_exit(test_module_exit); +MODULE_LICENSE("Dual MIT/GPL"); -- cgit v1.2.3-70-g09d2 From 6d3344324b5ae49fc8cb599a2c687e5607ba6e9f Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Mon, 4 Jun 2018 08:41:27 +0200 Subject: test_overflow: macrofy some more, do more tests for free Obviously a+b==b+a and a*b==b*a, but the implementation of the fallback checks are not entirely symmetric in how they treat a and b. So we might as well check the (b,a,r,of) tuple as well as the (a,b,r,of) one for + and *. Rather than more copy-paste, factor out the common part to check_one_op. Signed-off-by: Rasmus Villemoes Signed-off-by: Kees Cook --- lib/test_overflow.c | 48 ++++++++++++++++++++++-------------------------- 1 file changed, 22 insertions(+), 26 deletions(-) (limited to 'lib/test_overflow.c') diff --git a/lib/test_overflow.c b/lib/test_overflow.c index af01e46500be..fa87e283b149 100644 --- a/lib/test_overflow.c +++ b/lib/test_overflow.c @@ -211,35 +211,31 @@ DEFINE_TEST_ARRAY(s64) = { {0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false}, }; +#define check_one_op(t, fmt, op, sym, a, b, r, of) do { \ + t _r; \ + bool _of; \ + \ + _of = check_ ## op ## _overflow(a, b, &_r); \ + if (_of != of) { \ + pr_warn("expected "fmt" "sym" "fmt \ + " to%s overflow (type %s)\n", \ + a, b, of ? "" : " not", #t); \ + } \ + if (_r != r) { \ + pr_warn("expected "fmt" "sym" "fmt" == " \ + fmt", got "fmt" (type %s)\n", \ + a, b, r, _r, #t); \ + } \ +} while (0) + #define DEFINE_TEST_FUNC(t, fmt) \ static void __init do_test_ ## t(const struct test_ ## t *p) \ { \ - t r; \ - bool of; \ - \ - of = check_add_overflow(p->a, p->b, &r); \ - if (of != p->s_of) \ - pr_warn("expected "fmt" + "fmt" to%s overflow (type %s)\n", \ - p->a, p->b, p->s_of ? "" : " not", #t); \ - if (r != p->sum) \ - pr_warn("expected "fmt" + "fmt" == "fmt", got "fmt" (type %s)\n", \ - p->a, p->b, p->sum, r, #t); \ - \ - of = check_sub_overflow(p->a, p->b, &r); \ - if (of != p->d_of) \ - pr_warn("expected "fmt" - "fmt" to%s overflow (type %s)\n", \ - p->a, p->b, p->s_of ? "" : " not", #t); \ - if (r != p->diff) \ - pr_warn("expected "fmt" - "fmt" == "fmt", got "fmt" (type %s)\n", \ - p->a, p->b, p->diff, r, #t); \ - \ - of = check_mul_overflow(p->a, p->b, &r); \ - if (of != p->p_of) \ - pr_warn("expected "fmt" * "fmt" to%s overflow (type %s)\n", \ - p->a, p->b, p->p_of ? "" : " not", #t); \ - if (r != p->prod) \ - pr_warn("expected "fmt" * "fmt" == "fmt", got "fmt" (type %s)\n", \ - p->a, p->b, p->prod, r, #t); \ + check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of); \ + check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of); \ + check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of); \ + check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of); \ + check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of); \ } \ \ static void __init test_ ## t ## _overflow(void) { \ -- cgit v1.2.3-70-g09d2 From 8fee81aa4598484c073c845281a25d94fb204cf6 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 9 May 2018 22:13:28 -0700 Subject: test_overflow: Report test failures This adjusts the overflow test to report failures, and prepares to add allocation tests. Signed-off-by: Kees Cook --- lib/test_overflow.c | 54 ++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 39 insertions(+), 15 deletions(-) (limited to 'lib/test_overflow.c') diff --git a/lib/test_overflow.c b/lib/test_overflow.c index fa87e283b149..501ed86205c4 100644 --- a/lib/test_overflow.c +++ b/lib/test_overflow.c @@ -220,30 +220,38 @@ DEFINE_TEST_ARRAY(s64) = { pr_warn("expected "fmt" "sym" "fmt \ " to%s overflow (type %s)\n", \ a, b, of ? "" : " not", #t); \ + err = 1; \ } \ if (_r != r) { \ pr_warn("expected "fmt" "sym" "fmt" == " \ fmt", got "fmt" (type %s)\n", \ a, b, r, _r, #t); \ + err = 1; \ } \ } while (0) #define DEFINE_TEST_FUNC(t, fmt) \ -static void __init do_test_ ## t(const struct test_ ## t *p) \ +static int __init do_test_ ## t(const struct test_ ## t *p) \ { \ + int err = 0; \ + \ check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of); \ check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of); \ check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of); \ check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of); \ check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of); \ + \ + return err; \ } \ \ -static void __init test_ ## t ## _overflow(void) { \ +static int __init test_ ## t ## _overflow(void) { \ + int err = 0; \ unsigned i; \ \ pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests)); \ for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i) \ - do_test_ ## t(&t ## _tests[i]); \ + err |= do_test_ ## t(&t ## _tests[i]); \ + return err; \ } DEFINE_TEST_FUNC(u8, "%d"); @@ -257,27 +265,43 @@ DEFINE_TEST_FUNC(u64, "%llu"); DEFINE_TEST_FUNC(s64, "%lld"); #endif -static int __init test_overflow(void) +static int __init test_overflow_calculation(void) { - test_u8_overflow(); - test_s8_overflow(); - test_u16_overflow(); - test_s16_overflow(); - test_u32_overflow(); - test_s32_overflow(); + int err = 0; + + err |= test_u8_overflow(); + err |= test_s8_overflow(); + err |= test_u16_overflow(); + err |= test_s16_overflow(); + err |= test_u32_overflow(); + err |= test_s32_overflow(); #if BITS_PER_LONG == 64 - test_u64_overflow(); - test_s64_overflow(); + err |= test_u64_overflow(); + err |= test_s64_overflow(); #endif - pr_info("done\n"); + return err; +} + +static int __init test_module_init(void) +{ + int err = 0; + + err |= test_overflow_calculation(); + + if (err) { + pr_warn("FAIL!\n"); + err = -EINVAL; + } else { + pr_info("all tests passed\n"); + } - return 0; + return err; } static void __exit test_module_exit(void) { } -module_init(test_overflow); +module_init(test_module_init); module_exit(test_module_exit); MODULE_LICENSE("Dual MIT/GPL"); -- cgit v1.2.3-70-g09d2 From ca90800a91ba723d78ded634d037c1d2df8b54d6 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 10 May 2018 16:40:03 -0700 Subject: test_overflow: Add memory allocation overflow tests Make sure that the memory allocators are behaving as expected in the face of overflows of multiplied arguments or when using the array_size()-family helpers. Example output of new tests (with the expected __alloc_pages_slowpath and vmalloc warnings about refusing giant allocations removed): [ 93.062076] test_overflow: kmalloc detected saturation [ 93.062988] test_overflow: kmalloc_node detected saturation [ 93.063818] test_overflow: kzalloc detected saturation [ 93.064539] test_overflow: kzalloc_node detected saturation [ 93.120386] test_overflow: kvmalloc detected saturation [ 93.143458] test_overflow: kvmalloc_node detected saturation [ 93.166861] test_overflow: kvzalloc detected saturation [ 93.189924] test_overflow: kvzalloc_node detected saturation [ 93.221671] test_overflow: vmalloc detected saturation [ 93.246326] test_overflow: vmalloc_node detected saturation [ 93.270260] test_overflow: vzalloc detected saturation [ 93.293824] test_overflow: vzalloc_node detected saturation [ 93.294597] test_overflow: devm_kmalloc detected saturation [ 93.295383] test_overflow: devm_kzalloc detected saturation [ 93.296217] test_overflow: all tests passed Signed-off-by: Kees Cook --- lib/test_overflow.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) (limited to 'lib/test_overflow.c') diff --git a/lib/test_overflow.c b/lib/test_overflow.c index 501ed86205c4..aecbbb217305 100644 --- a/lib/test_overflow.c +++ b/lib/test_overflow.c @@ -4,11 +4,15 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include +#include #include #include +#include #include +#include #define DEFINE_TEST_ARRAY(t) \ static const struct test_ ## t { \ @@ -283,11 +287,117 @@ static int __init test_overflow_calculation(void) return err; } +/* + * Deal with the various forms of allocator arguments. See comments above + * the DEFINE_TEST_ALLOC() instances for mapping of the "bits". + */ +#define alloc010(alloc, arg, sz) alloc(sz, GFP_KERNEL) +#define alloc011(alloc, arg, sz) alloc(sz, GFP_KERNEL, NUMA_NO_NODE) +#define alloc000(alloc, arg, sz) alloc(sz) +#define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE) +#define alloc110(alloc, arg, sz) alloc(arg, sz, GFP_KERNEL) +#define free0(free, arg, ptr) free(ptr) +#define free1(free, arg, ptr) free(arg, ptr) + +/* Wrap around to 8K */ +#define TEST_SIZE (9 << PAGE_SHIFT) + +#define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\ +static int __init test_ ## func (void *arg) \ +{ \ + volatile size_t a = TEST_SIZE; \ + volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1; \ + void *ptr; \ + \ + /* Tiny allocation test. */ \ + ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\ + if (!ptr) { \ + pr_warn(#func " failed regular allocation?!\n"); \ + return 1; \ + } \ + free ## want_arg (free_func, arg, ptr); \ + \ + /* Wrapped allocation test. */ \ + ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, \ + a * b); \ + if (!ptr) { \ + pr_warn(#func " unexpectedly failed bad wrapping?!\n"); \ + return 1; \ + } \ + free ## want_arg (free_func, arg, ptr); \ + \ + /* Saturated allocation test. */ \ + ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, \ + array_size(a, b)); \ + if (ptr) { \ + pr_warn(#func " missed saturation!\n"); \ + free ## want_arg (free_func, arg, ptr); \ + return 1; \ + } \ + pr_info(#func " detected saturation\n"); \ + return 0; \ +} + +/* + * Allocator uses a trailing node argument --------+ (e.g. kmalloc_node()) + * Allocator uses the gfp_t argument -----------+ | (e.g. kmalloc()) + * Allocator uses a special leading argument + | | (e.g. devm_kmalloc()) + * | | | + */ +DEFINE_TEST_ALLOC(kmalloc, kfree, 0, 1, 0); +DEFINE_TEST_ALLOC(kmalloc_node, kfree, 0, 1, 1); +DEFINE_TEST_ALLOC(kzalloc, kfree, 0, 1, 0); +DEFINE_TEST_ALLOC(kzalloc_node, kfree, 0, 1, 1); +DEFINE_TEST_ALLOC(vmalloc, vfree, 0, 0, 0); +DEFINE_TEST_ALLOC(vmalloc_node, vfree, 0, 0, 1); +DEFINE_TEST_ALLOC(vzalloc, vfree, 0, 0, 0); +DEFINE_TEST_ALLOC(vzalloc_node, vfree, 0, 0, 1); +DEFINE_TEST_ALLOC(kvmalloc, kvfree, 0, 1, 0); +DEFINE_TEST_ALLOC(kvmalloc_node, kvfree, 0, 1, 1); +DEFINE_TEST_ALLOC(kvzalloc, kvfree, 0, 1, 0); +DEFINE_TEST_ALLOC(kvzalloc_node, kvfree, 0, 1, 1); +DEFINE_TEST_ALLOC(devm_kmalloc, devm_kfree, 1, 1, 0); +DEFINE_TEST_ALLOC(devm_kzalloc, devm_kfree, 1, 1, 0); + +static int __init test_overflow_allocation(void) +{ + const char device_name[] = "overflow-test"; + struct device *dev; + int err = 0; + + /* Create dummy device for devm_kmalloc()-family tests. */ + dev = root_device_register(device_name); + if (!dev) { + pr_warn("Cannot register test device\n"); + return 1; + } + + err |= test_kmalloc(NULL); + err |= test_kmalloc_node(NULL); + err |= test_kzalloc(NULL); + err |= test_kzalloc_node(NULL); + err |= test_kvmalloc(NULL); + err |= test_kvmalloc_node(NULL); + err |= test_kvzalloc(NULL); + err |= test_kvzalloc_node(NULL); + err |= test_vmalloc(NULL); + err |= test_vmalloc_node(NULL); + err |= test_vzalloc(NULL); + err |= test_vzalloc_node(NULL); + err |= test_devm_kmalloc(dev); + err |= test_devm_kzalloc(dev); + + device_unregister(dev); + + return err; +} + static int __init test_module_init(void) { int err = 0; err |= test_overflow_calculation(); + err |= test_overflow_allocation(); if (err) { pr_warn("FAIL!\n"); -- cgit v1.2.3-70-g09d2 From 8958fd411ba08aa3ac1aeb19828abaf9cf33f7b8 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 12 Jun 2018 15:04:33 +0300 Subject: test_overflow: fix an IS_ERR() vs NULL bug root_device_register() returns error pointers, it never returns NULL. Fixes: ca90800a91ba ("test_overflow: Add memory allocation overflow tests") Signed-off-by: Dan Carpenter Signed-off-by: Kees Cook --- lib/test_overflow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/test_overflow.c') diff --git a/lib/test_overflow.c b/lib/test_overflow.c index aecbbb217305..2278fe05a1b0 100644 --- a/lib/test_overflow.c +++ b/lib/test_overflow.c @@ -367,7 +367,7 @@ static int __init test_overflow_allocation(void) /* Create dummy device for devm_kmalloc()-family tests. */ dev = root_device_register(device_name); - if (!dev) { + if (IS_ERR(dev)) { pr_warn("Cannot register test device\n"); return 1; } -- cgit v1.2.3-70-g09d2 From d36b6ad27c7b95e3f6bfbf6ea33757c8e8accf01 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 1 Aug 2018 14:25:40 -0700 Subject: test_overflow: Add shift overflow tests This adds overflow tests for the new check_shift_overflow() helper to validate overflow, signedness glitches, storage glitches, etc. Co-developed-by: Rasmus Villemoes Signed-off-by: Kees Cook Signed-off-by: Jason Gunthorpe --- lib/test_overflow.c | 198 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 197 insertions(+), 1 deletion(-) (limited to 'lib/test_overflow.c') diff --git a/lib/test_overflow.c b/lib/test_overflow.c index 2278fe05a1b0..fc680562d8b6 100644 --- a/lib/test_overflow.c +++ b/lib/test_overflow.c @@ -252,7 +252,8 @@ static int __init test_ ## t ## _overflow(void) { \ int err = 0; \ unsigned i; \ \ - pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests)); \ + pr_info("%-3s: %zu arithmetic tests\n", #t, \ + ARRAY_SIZE(t ## _tests)); \ for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i) \ err |= do_test_ ## t(&t ## _tests[i]); \ return err; \ @@ -287,6 +288,200 @@ static int __init test_overflow_calculation(void) return err; } +static int __init test_overflow_shift(void) +{ + int err = 0; + +/* Args are: value, shift, type, expected result, overflow expected */ +#define TEST_ONE_SHIFT(a, s, t, expect, of) ({ \ + int __failed = 0; \ + typeof(a) __a = (a); \ + typeof(s) __s = (s); \ + t __e = (expect); \ + t __d; \ + bool __of = check_shl_overflow(__a, __s, &__d); \ + if (__of != of) { \ + pr_warn("expected (%s)(%s << %s) to%s overflow\n", \ + #t, #a, #s, of ? "" : " not"); \ + __failed = 1; \ + } else if (!__of && __d != __e) { \ + pr_warn("expected (%s)(%s << %s) == %s\n", \ + #t, #a, #s, #expect); \ + if ((t)-1 < 0) \ + pr_warn("got %lld\n", (s64)__d); \ + else \ + pr_warn("got %llu\n", (u64)__d); \ + __failed = 1; \ + } \ + if (!__failed) \ + pr_info("ok: (%s)(%s << %s) == %s\n", #t, #a, #s, \ + of ? "overflow" : #expect); \ + __failed; \ +}) + + /* Sane shifts. */ + err |= TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false); + err |= TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false); + err |= TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false); + err |= TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false); + err |= TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false); + err |= TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false); + err |= TEST_ONE_SHIFT(1, 0, int, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 16, int, 1 << 16, false); + err |= TEST_ONE_SHIFT(1, 30, int, 1 << 30, false); + err |= TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false); + err |= TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false); + err |= TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false); + err |= TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false); + err |= TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false); + err |= TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false); + err |= TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false); + err |= TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false); + err |= TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false); + err |= TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false); + err |= TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false); + err |= TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false); + err |= TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false); + err |= TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64, + 0xFFFFFFFFULL << 32, false); + + /* Sane shift: start and end with 0, without a too-wide shift. */ + err |= TEST_ONE_SHIFT(0, 7, u8, 0, false); + err |= TEST_ONE_SHIFT(0, 15, u16, 0, false); + err |= TEST_ONE_SHIFT(0, 31, unsigned int, 0, false); + err |= TEST_ONE_SHIFT(0, 31, u32, 0, false); + err |= TEST_ONE_SHIFT(0, 63, u64, 0, false); + + /* Sane shift: start and end with 0, without reaching signed bit. */ + err |= TEST_ONE_SHIFT(0, 6, s8, 0, false); + err |= TEST_ONE_SHIFT(0, 14, s16, 0, false); + err |= TEST_ONE_SHIFT(0, 30, int, 0, false); + err |= TEST_ONE_SHIFT(0, 30, s32, 0, false); + err |= TEST_ONE_SHIFT(0, 62, s64, 0, false); + + /* Overflow: shifted the bit off the end. */ + err |= TEST_ONE_SHIFT(1, 8, u8, 0, true); + err |= TEST_ONE_SHIFT(1, 16, u16, 0, true); + err |= TEST_ONE_SHIFT(1, 32, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(1, 32, u32, 0, true); + err |= TEST_ONE_SHIFT(1, 64, u64, 0, true); + + /* Overflow: shifted into the signed bit. */ + err |= TEST_ONE_SHIFT(1, 7, s8, 0, true); + err |= TEST_ONE_SHIFT(1, 15, s16, 0, true); + err |= TEST_ONE_SHIFT(1, 31, int, 0, true); + err |= TEST_ONE_SHIFT(1, 31, s32, 0, true); + err |= TEST_ONE_SHIFT(1, 63, s64, 0, true); + + /* Overflow: high bit falls off unsigned types. */ + /* 10010110 */ + err |= TEST_ONE_SHIFT(150, 1, u8, 0, true); + /* 1000100010010110 */ + err |= TEST_ONE_SHIFT(34966, 1, u16, 0, true); + /* 10000100000010001000100010010110 */ + err |= TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true); + err |= TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true); + /* 1000001000010000010000000100000010000100000010001000100010010110 */ + err |= TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true); + + /* Overflow: bit shifted into signed bit on signed types. */ + /* 01001011 */ + err |= TEST_ONE_SHIFT(75, 1, s8, 0, true); + /* 0100010001001011 */ + err |= TEST_ONE_SHIFT(17483, 1, s16, 0, true); + /* 01000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(1107575883, 1, s32, 0, true); + err |= TEST_ONE_SHIFT(1107575883, 1, int, 0, true); + /* 0100000100001000001000000010000001000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true); + + /* Overflow: bit shifted past signed bit on signed types. */ + /* 01001011 */ + err |= TEST_ONE_SHIFT(75, 2, s8, 0, true); + /* 0100010001001011 */ + err |= TEST_ONE_SHIFT(17483, 2, s16, 0, true); + /* 01000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(1107575883, 2, s32, 0, true); + err |= TEST_ONE_SHIFT(1107575883, 2, int, 0, true); + /* 0100000100001000001000000010000001000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true); + + /* Overflow: values larger than destination type. */ + err |= TEST_ONE_SHIFT(0x100, 0, u8, 0, true); + err |= TEST_ONE_SHIFT(0xFF, 0, s8, 0, true); + err |= TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true); + err |= TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true); + err |= TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true); + + /* Nonsense: negative initial value. */ + err |= TEST_ONE_SHIFT(-1, 0, s8, 0, true); + err |= TEST_ONE_SHIFT(-1, 0, u8, 0, true); + err |= TEST_ONE_SHIFT(-5, 0, s16, 0, true); + err |= TEST_ONE_SHIFT(-5, 0, u16, 0, true); + err |= TEST_ONE_SHIFT(-10, 0, int, 0, true); + err |= TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(-100, 0, s32, 0, true); + err |= TEST_ONE_SHIFT(-100, 0, u32, 0, true); + err |= TEST_ONE_SHIFT(-10000, 0, s64, 0, true); + err |= TEST_ONE_SHIFT(-10000, 0, u64, 0, true); + + /* Nonsense: negative shift values. */ + err |= TEST_ONE_SHIFT(0, -5, s8, 0, true); + err |= TEST_ONE_SHIFT(0, -5, u8, 0, true); + err |= TEST_ONE_SHIFT(0, -10, s16, 0, true); + err |= TEST_ONE_SHIFT(0, -10, u16, 0, true); + err |= TEST_ONE_SHIFT(0, -15, int, 0, true); + err |= TEST_ONE_SHIFT(0, -15, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(0, -20, s32, 0, true); + err |= TEST_ONE_SHIFT(0, -20, u32, 0, true); + err |= TEST_ONE_SHIFT(0, -30, s64, 0, true); + err |= TEST_ONE_SHIFT(0, -30, u64, 0, true); + + /* Overflow: shifted at or beyond entire type's bit width. */ + err |= TEST_ONE_SHIFT(0, 8, u8, 0, true); + err |= TEST_ONE_SHIFT(0, 9, u8, 0, true); + err |= TEST_ONE_SHIFT(0, 8, s8, 0, true); + err |= TEST_ONE_SHIFT(0, 9, s8, 0, true); + err |= TEST_ONE_SHIFT(0, 16, u16, 0, true); + err |= TEST_ONE_SHIFT(0, 17, u16, 0, true); + err |= TEST_ONE_SHIFT(0, 16, s16, 0, true); + err |= TEST_ONE_SHIFT(0, 17, s16, 0, true); + err |= TEST_ONE_SHIFT(0, 32, u32, 0, true); + err |= TEST_ONE_SHIFT(0, 33, u32, 0, true); + err |= TEST_ONE_SHIFT(0, 32, int, 0, true); + err |= TEST_ONE_SHIFT(0, 33, int, 0, true); + err |= TEST_ONE_SHIFT(0, 32, s32, 0, true); + err |= TEST_ONE_SHIFT(0, 33, s32, 0, true); + err |= TEST_ONE_SHIFT(0, 64, u64, 0, true); + err |= TEST_ONE_SHIFT(0, 65, u64, 0, true); + err |= TEST_ONE_SHIFT(0, 64, s64, 0, true); + err |= TEST_ONE_SHIFT(0, 65, s64, 0, true); + + /* + * Corner case: for unsigned types, we fail when we've shifted + * through the entire width of bits. For signed types, we might + * want to match this behavior, but that would mean noticing if + * we shift through all but the signed bit, and this is not + * currently detected (but we'll notice an overflow into the + * signed bit). So, for now, we will test this condition but + * mark it as not expected to overflow. + */ + err |= TEST_ONE_SHIFT(0, 7, s8, 0, false); + err |= TEST_ONE_SHIFT(0, 15, s16, 0, false); + err |= TEST_ONE_SHIFT(0, 31, int, 0, false); + err |= TEST_ONE_SHIFT(0, 31, s32, 0, false); + err |= TEST_ONE_SHIFT(0, 63, s64, 0, false); + + return err; +} + /* * Deal with the various forms of allocator arguments. See comments above * the DEFINE_TEST_ALLOC() instances for mapping of the "bits". @@ -397,6 +592,7 @@ static int __init test_module_init(void) int err = 0; err |= test_overflow_calculation(); + err |= test_overflow_shift(); err |= test_overflow_allocation(); if (err) { -- cgit v1.2.3-70-g09d2