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scd: Fix "Conflicting usage" bug. 

* scd/apdu.c (apdu_close_reader): Call CLOSE_READER method even if we
  got an error from apdu_disconnect.
* scd/app-common.h (no_reuse): Remove.
* scd/app.c (application_notify_card_reset): Deallocate APP here.
(select_application, release_application): Don't use NO_REUSE.

--

Reproducible scenario: Invoke gpg --card-edit session from a terminal.
Invoke another gpg --card-edit session from another.  Remove a token.
Insert a token again.  Type RET on both terminals.  One of terminal
answers "Conflicting usage".

Perhaps, having NO_REUSE field was to avoid race conditions.  Now,
APP can be safely deallocated by application_notify_card_reset.

Thanks to the2nd.
This commit is contained in:
NIIBE Yutaka 2015-12-03 11:26:24 +09:00
parent 11b2691edd
commit f42c50dbf0
3 changed files with 11 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
scd/apdu.c
View File

@ -3215,9 +3215,12 @@ apdu_close_reader (int slot)
sw = apdu_disconnect (slot);
if (sw)
{
/*
* When the reader/token was removed it might come here.
* It should go through to call CLOSE_READER even if we got an error.
*/
if (DBG_READER)
log_debug ("leave: apdu_close_reader => 0x%x (apdu_disconnect)\n", sw);
return sw;
log_debug ("apdu_close_reader => 0x%x (apdu_disconnect)\n", sw);
}
if (reader_table[slot].close_reader)
{

5
scd/app-common.h
View File

@ -47,11 +47,6 @@ struct app_ctx_s {
operations the particular function pointer is set to NULL */
unsigned int ref_count;
/* Flag indicating that a reset has been done for that application
and that this context is merely lingering and just should not be
reused. */
int no_reuse;
/* Used reader slot. */
int slot;

27
scd/app.c
View File

@ -175,9 +175,12 @@ application_notify_card_reset (int slot)
/* FIXME: We are ignoring any error value here. */
lock_reader (slot, NULL);
/* Mark application as non-reusable. */
/* Release the APP, as it's not reusable any more. */
if (lock_table[slot].app)
lock_table[slot].app->no_reuse = 1;
{
deallocate_app (lock_table[slot].app);
lock_table[slot].app = NULL;
}
/* Deallocate a saved application for that slot, so that we won't
try to reuse it. If there is no saved application, set a flag so
@ -251,16 +254,6 @@ select_application (ctrl_t ctrl, int slot, const char *name, app_t *r_app)
return gpg_error (GPG_ERR_CONFLICT);
}
/* Don't use a non-reusable marked application. */
if (app && app->no_reuse)
{
unlock_reader (slot);
log_info ("lingering application '%s' in use by reader %d"
" - can't switch\n",
app->apptype? app->apptype:"?", slot);
return gpg_error (GPG_ERR_CONFLICT);
}
/* If we don't have an app, check whether we have a saved
application for that slot. This is useful so that a card does
not get reset even if only one session is using the card - this
@ -495,15 +488,7 @@ release_application (app_t app)
if (lock_table[slot].last_app)
deallocate_app (lock_table[slot].last_app);
if (app->no_reuse)
{
/* If we shall not re-use the application we can't save it for
later use. */
deallocate_app (app);
lock_table[slot].last_app = NULL;
}
else
lock_table[slot].last_app = lock_table[slot].app;
lock_table[slot].last_app = lock_table[slot].app;
lock_table[slot].app = NULL;
unlock_reader (slot);
}