From cabe58b0f8542d5c3dd1eca0b4def50bee1ffab4 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 25 Jan 2024 17:32:10 +0000 Subject: [PATCH] tests/qtest/xlnx-versal-trng-test.c: Drop use of variable length array This test program is the last use of any variable length array in the codebase. If we can get rid of all uses of VLAs we can make the compiler error on new additions. This is a defensive measure against security bugs where an on-stack dynamic allocation isn't correctly size-checked (e.g. CVE-2021-3527). In this case the test code didn't even want a variable-sized array, it was just accidentally using syntax that gave it one. (The array size for C has to be an actual constant expression, not just something that happens to be known to be constant...) Remove the VLA usage. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Thomas Huth Reviewed-by: Zhao Liu Message-id: 20240125173211.1786196-2-peter.maydell@linaro.org --- tests/qtest/xlnx-versal-trng-test.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/tests/qtest/xlnx-versal-trng-test.c b/tests/qtest/xlnx-versal-trng-test.c index cef4e575bb..ba86f39d13 100644 --- a/tests/qtest/xlnx-versal-trng-test.c +++ b/tests/qtest/xlnx-versal-trng-test.c @@ -298,10 +298,13 @@ static size_t trng_collect(uint32_t *rnd, size_t cnt) return i; } +/* These tests all generate 512 bits of random data with the device */ +#define TEST_DATA_WORDS (512 / 32) + static void trng_test_autogen(void) { - const size_t cnt = 512 / 32; - uint32_t rng[cnt], prng[cnt]; + const size_t cnt = TEST_DATA_WORDS; + uint32_t rng[TEST_DATA_WORDS], prng[TEST_DATA_WORDS]; size_t n; trng_reset(); @@ -343,8 +346,8 @@ static void trng_test_autogen(void) static void trng_test_oneshot(void) { - const size_t cnt = 512 / 32; - uint32_t rng[cnt]; + const size_t cnt = TEST_DATA_WORDS; + uint32_t rng[TEST_DATA_WORDS]; size_t n; trng_reset(); @@ -370,8 +373,8 @@ static void trng_test_oneshot(void) static void trng_test_per_str(void) { - const size_t cnt = 512 / 32; - uint32_t rng[cnt], prng[cnt]; + const size_t cnt = TEST_DATA_WORDS; + uint32_t rng[TEST_DATA_WORDS], prng[TEST_DATA_WORDS]; size_t n; trng_reset(); @@ -415,8 +418,8 @@ static void trng_test_forced_prng(void) const char *prop = "forced-prng"; const uint64_t seed = 0xdeadbeefbad1bad0ULL; - const size_t cnt = 512 / 32; - uint32_t rng[cnt], prng[cnt]; + const size_t cnt = TEST_DATA_WORDS; + uint32_t rng[TEST_DATA_WORDS], prng[TEST_DATA_WORDS]; size_t n; trng_reset();