diff options
author | Andy Polyakov <appro@openssl.org> | 2018-07-20 13:23:42 +0200 |
---|---|---|
committer | Andy Polyakov <appro@openssl.org> | 2018-07-25 16:37:35 +0200 |
commit | 80ae7285e1994d35c84519bf9e038b11d9942875 (patch) | |
tree | 077bf94bf38f4898d24d1761963f2f04b7ea3308 | |
parent | ceb8e32cbc9f6ddd17c5639a721f5314eb1f3acc (diff) |
crypto/init.c: use destructor_key even as guard in OPENSSL_thread_stop.
Problem was that Windows threads that were terminating before libcrypto
was initialized were referencing uninitialized or possibly even
unrelated thread local storage index.
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6752)
-rw-r--r-- | crypto/init.c | 54 |
1 files changed, 35 insertions, 19 deletions
diff --git a/crypto/init.c b/crypto/init.c index 2c8b48ff5b..7b69927218 100644 --- a/crypto/init.c +++ b/crypto/init.c @@ -30,11 +30,25 @@ static int stopped = 0; -static void ossl_init_thread_stop(struct thread_local_inits_st *locals); +/* + * Since per-thread-specific-data destructors are not universally + * available, i.e. not on Windows, only below CRYPTO_THREAD_LOCAL key + * is assumed to have destructor associated. And then an effort is made + * to call this single destructor on non-pthread platform[s]. + * + * Initial value is "impossible". It is used as guard value to shortcut + * destructor for threads terminating before libcrypto is initialized or + * after it's de-initialized. Access to the key doesn't have to be + * serialized for the said threads, because they didn't use libcrypto + * and it doesn't matter if they pick "impossible" or derefernce real + * key value and pull NULL past initialization in the first thread that + * intends to use libcrypto. + */ +static CRYPTO_THREAD_LOCAL destructor_key = (CRYPTO_THREAD_LOCAL)-1; -static CRYPTO_THREAD_LOCAL threadstopkey; +static void ossl_init_thread_stop(struct thread_local_inits_st *locals); -static void ossl_init_thread_stop_wrap(void *local) +static void ossl_init_thread_destructor(void *local) { ossl_init_thread_stop((struct thread_local_inits_st *)local); } @@ -42,17 +56,17 @@ static void ossl_init_thread_stop_wrap(void *local) static struct thread_local_inits_st *ossl_init_get_thread_local(int alloc) { struct thread_local_inits_st *local = - CRYPTO_THREAD_get_local(&threadstopkey); + CRYPTO_THREAD_get_local(&destructor_key); - if (local == NULL && alloc) { - local = OPENSSL_zalloc(sizeof(*local)); - if (local != NULL && !CRYPTO_THREAD_set_local(&threadstopkey, local)) { + if (alloc) { + if (local == NULL + && (local = OPENSSL_zalloc(sizeof(*local))) != NULL + && !CRYPTO_THREAD_set_local(&destructor_key, local)) { OPENSSL_free(local); return NULL; } - } - if (!alloc) { - CRYPTO_THREAD_set_local(&threadstopkey, NULL); + } else { + CRYPTO_THREAD_set_local(&destructor_key, NULL); } return local; @@ -71,17 +85,15 @@ static CRYPTO_ONCE base = CRYPTO_ONCE_STATIC_INIT; static int base_inited = 0; DEFINE_RUN_ONCE_STATIC(ossl_init_base) { + CRYPTO_THREAD_LOCAL key; + #ifdef OPENSSL_INIT_DEBUG fprintf(stderr, "OPENSSL_INIT: ossl_init_base: Setting up stop handlers\n"); #endif #ifndef OPENSSL_NO_CRYPTO_MDEBUG ossl_malloc_setup_failures(); #endif - /* - * We use a dummy thread local key here. We use the destructor to detect - * when the thread is going to stop (where that feature is available) - */ - if (!CRYPTO_THREAD_init_local(&threadstopkey, ossl_init_thread_stop_wrap)) + if (!CRYPTO_THREAD_init_local(&key, ossl_init_thread_destructor)) return 0; if ((init_lock = CRYPTO_THREAD_lock_new()) == NULL) goto err; @@ -91,6 +103,7 @@ DEFINE_RUN_ONCE_STATIC(ossl_init_base) #endif OPENSSL_cpuid_setup(); + destructor_key = key; base_inited = 1; return 1; @@ -101,7 +114,7 @@ err: CRYPTO_THREAD_lock_free(init_lock); init_lock = NULL; - CRYPTO_THREAD_cleanup_local(&threadstopkey); + CRYPTO_THREAD_cleanup_local(&key); return 0; } @@ -396,8 +409,8 @@ static void ossl_init_thread_stop(struct thread_local_inits_st *locals) void OPENSSL_thread_stop(void) { - ossl_init_thread_stop( - (struct thread_local_inits_st *)ossl_init_get_thread_local(0)); + if (destructor_key != (CRYPTO_THREAD_LOCAL)-1) + ossl_init_thread_stop(ossl_init_get_thread_local(0)); } int ossl_init_thread_start(uint64_t opts) @@ -442,6 +455,7 @@ int ossl_init_thread_start(uint64_t opts) void OPENSSL_cleanup(void) { OPENSSL_INIT_STOP *currhandler, *lasthandler; + CRYPTO_THREAD_LOCAL key; /* If we've not been inited then no need to deinit */ if (!base_inited) @@ -501,7 +515,9 @@ void OPENSSL_cleanup(void) err_free_strings_int(); } - CRYPTO_THREAD_cleanup_local(&threadstopkey); + key = destructor_key; + destructor_key = (CRYPTO_THREAD_LOCAL)-1; + CRYPTO_THREAD_cleanup_local(&key); #ifdef OPENSSL_INIT_DEBUG fprintf(stderr, "OPENSSL_INIT: OPENSSL_cleanup: " |