ITS#7022 NSS_Init* functions are not thread safe

The NSS_InitContext et. al, and their corresponding shutdown functions,
are not thread safe.  There can only be one thread at a time calling
these functions.  Protect the calls with a mutex.  Create the mutex
using a PR_CallOnce to ensure that the mutex is only created once and
not used before created.  Move the registration of the nss shutdown
callback to also use a PR_CallOnce.  Removed the call to
SSL_ClearSessionCache() because it is always called at shutdown, and we must
not call it more than once.
This commit is contained in:
Rich Megginson 2011-08-16 12:01:16 -06:00 committed by Howard Chu
parent 3dae953fd6
commit a7aac14d2a

View File

@ -130,9 +130,29 @@ static int tlsm_init( void );
#ifdef LDAP_R_COMPILE
/* it doesn't seem guaranteed that a client will call
tlsm_thr_init in a non-threaded context - so we have
to wrap the mutex creation in a prcallonce
*/
static ldap_pvt_thread_mutex_t tlsm_init_mutex;
static PRCallOnceType tlsm_init_mutex_callonce = {0,0};
static PRStatus PR_CALLBACK
tlsm_thr_init_callonce( void )
{
if ( ldap_pvt_thread_mutex_init( &tlsm_init_mutex ) ) {
Debug( LDAP_DEBUG_ANY,
"TLS: could not create mutex for moznss initialization: %d\n", errno, 0, 0 );
return PR_FAILURE;
}
return PR_SUCCESS;
}
static void
tlsm_thr_init( void )
{
( void )PR_CallOnce( &tlsm_init_mutex_callonce, tlsm_thr_init_callonce );
}
#endif /* LDAP_R_COMPILE */
@ -1079,7 +1099,6 @@ tlsm_nss_shutdown_cb( void *appData, void *nssData )
SECStatus rc = SECSuccess;
SSL_ShutdownServerSessionIDCache();
SSL_ClearSessionCache();
if ( pem_module ) {
SECMOD_UnloadUserModule( pem_module );
@ -1089,6 +1108,24 @@ tlsm_nss_shutdown_cb( void *appData, void *nssData )
return rc;
}
static PRCallOnceType tlsm_register_shutdown_callonce = {0,0};
static PRStatus PR_CALLBACK
tlsm_register_nss_shutdown_cb( void )
{
if ( SECSuccess == NSS_RegisterShutdown( tlsm_nss_shutdown_cb,
NULL ) ) {
return PR_SUCCESS;
}
return PR_FAILURE;
}
static PRStatus
tlsm_register_nss_shutdown( void )
{
return PR_CallOnce( &tlsm_register_shutdown_callonce,
tlsm_register_nss_shutdown_cb );
}
static int
tlsm_init_pem_module( void )
{
@ -1529,6 +1566,12 @@ tlsm_deferred_init( void *arg )
initParams.length = sizeof( initParams );
#endif /* HAVE_NSS_INITCONTEXT */
#ifdef LDAP_R_COMPILE
if ( PR_CallOnce( &tlsm_init_mutex_callonce, tlsm_thr_init_callonce ) ) {
return -1;
}
#endif /* LDAP_R_COMPILE */
#ifndef HAVE_NSS_INITCONTEXT
if ( !NSS_IsInitialized() ) {
#endif /* HAVE_NSS_INITCONTEXT */
@ -1556,6 +1599,10 @@ tlsm_deferred_init( void *arg )
}
tlsm_get_certdb_prefix( securitydir, &realcertdir, &prefix );
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_LOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
#ifdef HAVE_NSS_INITCONTEXT
#ifdef INITCONTEXT_HACK
if ( !NSS_IsInitialized() && ctx->tc_is_server ) {
@ -1574,6 +1621,10 @@ tlsm_deferred_init( void *arg )
rc = NSS_Initialize( realcertdir, prefix, prefix, SECMOD_DB, NSS_INIT_READONLY );
#endif
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_UNLOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
if ( rc != SECSuccess ) {
errcode = PORT_GetError();
if ( securitydirs[ii] != lt->lt_cacertdir) {
@ -1597,6 +1648,9 @@ tlsm_deferred_init( void *arg )
}
if ( errcode ) { /* no moznss db found, or not using moznss db */
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_LOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
#ifdef HAVE_NSS_INITCONTEXT
int flags = NSS_INIT_READONLY|NSS_INIT_NOCERTDB|NSS_INIT_NOMODDB;
#ifdef INITCONTEXT_HACK
@ -1615,6 +1669,9 @@ tlsm_deferred_init( void *arg )
#else
rc = NSS_NoDB_Init( NULL );
#endif
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_UNLOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
if ( rc != SECSuccess ) {
errcode = PORT_GetError();
Debug( LDAP_DEBUG_ANY,
@ -1628,13 +1685,22 @@ tlsm_deferred_init( void *arg )
#endif
/* initialize the PEM module */
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_LOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
if ( tlsm_init_pem_module() ) {
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_UNLOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
errcode = PORT_GetError();
Debug( LDAP_DEBUG_ANY,
"TLS: could not initialize moznss PEM module - error %d:%s.\n",
errcode, PR_ErrorToString( errcode, PR_LANGUAGE_I_DEFAULT ), 0 );
return -1;
}
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_UNLOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
if ( tlsm_init_ca_certs( ctx, lt->lt_cacertfile, lt->lt_cacertdir ) ) {
/* if we tried to use lt->lt_cacertdir as an NSS key/cert db, errcode
@ -1669,10 +1735,13 @@ tlsm_deferred_init( void *arg )
PK11_SetPasswordFunc( tlsm_pin_prompt );
/* register cleanup function */
/* delete the old one, if any */
NSS_UnregisterShutdown( tlsm_nss_shutdown_cb, NULL );
NSS_RegisterShutdown( tlsm_nss_shutdown_cb, NULL );
if ( tlsm_register_nss_shutdown() ) {
errcode = PORT_GetError();
Debug( LDAP_DEBUG_ANY,
"TLS: could not register NSS shutdown function: %d:%s\n",
errcode, PR_ErrorToString( errcode, PR_LANGUAGE_I_DEFAULT ), 0 );
return -1;
}
#ifndef HAVE_NSS_INITCONTEXT
}
#endif /* HAVE_NSS_INITCONTEXT */
@ -1884,6 +1953,9 @@ tlsm_clientauth_init( tlsm_ctx *ctx )
static void
tlsm_destroy( void )
{
#ifdef LDAP_R_COMPILE
ldap_pvt_thread_mutex_destroy( &tlsm_init_mutex );
#endif
}
static tls_ctx *
@ -1949,8 +2021,20 @@ tlsm_ctx_free ( tls_ctx *ctx )
PL_strfree( c->tc_slotname );
tlsm_free_pem_objs( c );
#ifdef HAVE_NSS_INITCONTEXT
if (c->tc_initctx)
NSS_ShutdownContext( c->tc_initctx );
if ( c->tc_initctx ) {
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_LOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
if ( NSS_ShutdownContext( c->tc_initctx ) ) {
PRErrorCode errcode = PR_GetError();
Debug( LDAP_DEBUG_ANY,
"TLS: could not shutdown NSS - error %d:%s.\n",
errcode, PR_ErrorToString( errcode, PR_LANGUAGE_I_DEFAULT ), 0 );
}
#ifdef LDAP_R_COMPILE
LDAP_MUTEX_UNLOCK( &tlsm_init_mutex );
#endif /* LDAP_R_COMPILE */
}
c->tc_initctx = NULL;
#endif /* HAVE_NSS_INITCONTEXT */
#ifdef LDAP_R_COMPILE