diff options
| author | Feng Jiang <jiangfeng@kylinos.cn> | 2026-04-03 19:28:47 -0600 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2026-04-04 18:42:44 -0600 |
| commit | 263dca234e5cc12aa8b434592ceb655538bf4ea4 (patch) | |
| tree | 85d310031b62550f1ed758afd861f78542181997 | |
| parent | ae45f896a40a07449d9b45d0395fb7245fdd75fc (diff) | |
lib/string_kunit: add correctness test for strnlen()
Add a KUnit test for strnlen() to verify correctness across
different string lengths and memory alignments. Use vmalloc()
to place the NUL character at the page boundary to ensure
over-reads are detected.
Suggested-by: Andy Shevchenko <andy@kernel.org>
Suggested-by: Kees Cook <kees@kernel.org>
Signed-off-by: Feng Jiang <jiangfeng@kylinos.cn>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20260130025018.172925-3-jiangfeng@kylinos.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>
| -rw-r--r-- | lib/tests/string_kunit.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c index 26962118768e..1c2d57e05624 100644 --- a/lib/tests/string_kunit.c +++ b/lib/tests/string_kunit.c @@ -133,6 +133,40 @@ static void string_test_strlen(struct kunit *test) vfree(buf); } +static void string_test_strnlen(struct kunit *test) +{ + size_t buf_size; + char *buf, *s; + + buf_size = PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1); + buf = vmalloc(buf_size); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf); + + memset(buf, 'A', buf_size); + + for (size_t offset = 0; offset < STRING_TEST_MAX_OFFSET; offset++) { + for (size_t len = 0; len <= STRING_TEST_MAX_LEN; len++) { + s = buf + buf_size - 1 - offset - len; + s[len] = '\0'; + + if (len > 0) + KUNIT_EXPECT_EQ(test, strnlen(s, len - 1), len - 1); + if (len > 1) + KUNIT_EXPECT_EQ(test, strnlen(s, len - 2), len - 2); + + KUNIT_EXPECT_EQ(test, strnlen(s, len), len); + + KUNIT_EXPECT_EQ(test, strnlen(s, len + 1), len); + KUNIT_EXPECT_EQ(test, strnlen(s, len + 2), len); + KUNIT_EXPECT_EQ(test, strnlen(s, len + 10), len); + + s[len] = 'A'; + } + } + + vfree(buf); +} + static void string_test_strchr(struct kunit *test) { const char *test_string = "abcdefghijkl"; @@ -648,6 +682,7 @@ static struct kunit_case string_test_cases[] = { KUNIT_CASE(string_test_memset32), KUNIT_CASE(string_test_memset64), KUNIT_CASE(string_test_strlen), + KUNIT_CASE(string_test_strnlen), KUNIT_CASE(string_test_strchr), KUNIT_CASE(string_test_strnchr), KUNIT_CASE(string_test_strspn), |