06c1c49d0c
A much better "unknown size" string pointer is available directly from
struct test, so use that instead of a global that isn't shared with
modules.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/lkml/YyCOHOchVuE/E7vS@dev-arch.thelio-3990X
Fixes: 875bfd5276 ("fortify: Add KUnit test for FORTIFY_SOURCE internals")
Cc: linux-hardening@vger.kernel.org
Build-tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
77 lines
2.0 KiB
C
77 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Runtime test cases for CONFIG_FORTIFY_SOURCE that aren't expected to
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* Oops the kernel on success. (For those, see drivers/misc/lkdtm/fortify.c)
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*
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* For corner cases with UBSAN, try testing with:
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*
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* ./tools/testing/kunit/kunit.py run --arch=x86_64 \
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* --kconfig_add CONFIG_FORTIFY_SOURCE=y \
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* --kconfig_add CONFIG_UBSAN=y \
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* --kconfig_add CONFIG_UBSAN_TRAP=y \
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* --kconfig_add CONFIG_UBSAN_BOUNDS=y \
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* --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \
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* --make_options LLVM=1 fortify
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <kunit/test.h>
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#include <linux/string.h>
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static const char array_of_10[] = "this is 10";
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static const char *ptr_of_11 = "this is 11!";
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static char array_unknown[] = "compiler thinks I might change";
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static void known_sizes_test(struct kunit *test)
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{
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KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
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KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
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KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11);
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KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX);
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/* Externally defined and dynamically sized string pointer: */
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KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX);
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}
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/* This is volatile so the optimizer can't perform DCE below. */
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static volatile int pick;
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/* Not inline to keep optimizer from figuring out which string we want. */
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static noinline size_t want_minus_one(int pick)
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{
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const char *str;
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switch (pick) {
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case 1:
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str = "4444";
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break;
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case 2:
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str = "333";
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break;
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default:
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str = "1";
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break;
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}
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return __compiletime_strlen(str);
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}
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static void control_flow_split_test(struct kunit *test)
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{
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KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
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}
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static struct kunit_case fortify_test_cases[] = {
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KUNIT_CASE(known_sizes_test),
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KUNIT_CASE(control_flow_split_test),
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{}
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};
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static struct kunit_suite fortify_test_suite = {
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.name = "fortify",
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.test_cases = fortify_test_cases,
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};
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kunit_test_suite(fortify_test_suite);
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MODULE_LICENSE("GPL");
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