scd: Fix a race condition for new_reader_slot.

* scd/apdu.c (reader_table_lock, apdu_init): New.
(new_reader_slot): Serialize by reader_table_lock.
* scd/app.c (lock_app, unlock_app, app_new_register): Fix error code
usage.
(initialize_module_command): Call apdu_init.
* scd/scdaemon.c (main): Handle error for initialize_module_command.

--

This is a long standing bug.  There are two different things; The
serialization of allocating a new SLOT, and the serialization of using
the SLOT.  The latter was implemented in new_reader_slot by lock_slot.
However, the former was not done.  Thus, there was a possible race where
a same SLOT is allocated to multiple threads.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/scd/scdaemon.h b/scd/scdaemon.h
index e18ebfe4c..22b17b49e 100644
--- a/scd/scdaemon.h
+++ b/scd/scdaemon.h
@@ -118,7 +118,7 @@ void scd_exit (int rc);
 const char *scd_get_socket_name (void);
 
 /*-- command.c --*/
-void initialize_module_command (void);
+gpg_error_t initialize_module_command (void);
 int  scd_command_handler (ctrl_t, int);
 void send_status_info (ctrl_t ctrl, const char *keyword, ...)
      GPGRT_ATTR_SENTINEL(1);