jhogberg
commented
1 year ago Thanks for your report! Something fishy is going on here. We appear to crash here because rand_meth_lock is NULL:
// #ifndef OPENSSL_NO_DEPRECATED_3_0 a bit higher up
const RAND_METHOD *RAND_get_rand_method(void)
{
const RAND_METHOD *tmp_meth = NULL;
// this is just pthread_once, and returns after do_rand_init runs. If multiple
// threads race they will wait until the first one finishes.
if (!RUN_ONCE(&rand_init, do_rand_init))
return NULL;
if (!CRYPTO_THREAD_write_lock(rand_meth_lock)) // <----
return NULL;This is weird since do_rand_init is supposed to initialize it:
DEFINE_RUN_ONCE_STATIC(do_rand_init)
{
# ifndef OPENSSL_NO_ENGINE
rand_engine_lock = CRYPTO_THREAD_lock_new();
if (rand_engine_lock == NULL)
return 0;
# endif
# ifndef OPENSSL_NO_DEPRECATED_3_0
rand_meth_lock = CRYPTO_THREAD_lock_new();
if (rand_meth_lock == NULL)
goto err;
# endif
if (!ossl_rand_pool_init())
goto err;
rand_inited = 1;
return 1;
err:
# ifndef OPENSSL_NO_DEPRECATED_3_0
CRYPTO_THREAD_lock_free(rand_meth_lock);
rand_meth_lock = NULL;
# endif
# ifndef OPENSSL_NO_ENGINE
CRYPTO_THREAD_lock_free(rand_engine_lock);
rand_engine_lock = NULL;
# endif
return 0;
}Checking the state of the rand_inited variable, it's 0, so we apparently haven't succeeded in initializing the lock. Now why would RUN_ONCE(&rand_init, do_rand_init) return non-zero if that failed?
# define DEFINE_RUN_ONCE_STATIC(init) \
static int init(void); \
static int init##_ossl_ret_ = 0; \
static void init##_ossl_(void) \
{ \
init##_ossl_ret_ = init(); \
} \
static int init(void)
// snip
# define RUN_ONCE(once, init) \
(CRYPTO_THREAD_run_once(once, init##_ossl_) ? init##_ossl_ret_ : 0)
// snip
int CRYPTO_THREAD_run_once(CRYPTO_ONCE *once, void (*init)(void))
{
if (pthread_once(once, init) != 0) // zero on success
return 0;
return 1;
}So, if CRYPTO_THREAD_run_once succeeds RUN_ONCE returns the value of do_rand_init_ossl_ret_, which has been set to the return value of do_rand_init. do_rand_init_ossl_ret_ is 1 while rand_inited is 0, which should not be possible. I'd really like to see some more core dumps if that can be arranged.
How long had the node been running before the crash? Did any previous calls to crypto:strong_rand_bytes/1 succeed?
hareen-kancharla
timofey-barmin
max-au
Describe the bug beam.smp crashes in strong_rand_bytes_nif (openssl 3 & Erlang 25) with the following stacktrace.
Erlang Version: 25.1.2 Crypto app version: crypto-5.1.2 OS: Ubuntu18
To Reproduce
Expected behavior beam.smp shouldn't crash.
Affected versions 25.1.2
Additional context archived_core_dumps.tar.bz2 has the coredump and the necessary .so files (corefile was too large to upload here)