Commit 80ae7285 authored by Andy Polyakov's avatar Andy Polyakov
Browse files

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: default avatarKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6752)
parent ceb8e32c

crypto/init.c

+35 −19
Original line number Diff line number Diff line
@@ -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: "