[gnome-settings-daemon/nssrwlock-lockread-util-crash] smartcard: Cancel cancellable when stopping

[Marek Kašík <mkasik src gnome org>]

commit a1c2685bc6b255f22b6ce4645c001d428cb67907
Author: Marek Kasik <mkasik redhat com>
Date:   Wed May 22 14:56:42 2019 +0200

    smartcard: Cancel cancellable when stopping
    
    self->cancellable in GsdSmartcardManager is not cancelled
    at gsd_smartcard_manager_stop() and hence some callbacks are
    still called after unload_nss() which clears SECMODListLock
    which is used by SECMOD_GetReadLock() / SECMOD_ReleaseReadLock().
    
    This leads to crashes in NSSRWLock_LockRead_Util() and
    NSSRWLock_UnlockRead_Util() probably.
    
    Also check for return value of g_cancellable_connect().
    
    See https://bugzilla.redhat.com/show_bug.cgi?id=1646359,
    https://bugzilla.redhat.com/show_bug.cgi?id=1688791 and
    their duplicates for additional info.

 plugins/smartcard/gsd-smartcard-manager.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/plugins/smartcard/gsd-smartcard-manager.c b/plugins/smartcard/gsd-smartcard-manager.c
index 014c17be..da1e0d6d 100644
--- a/plugins/smartcard/gsd-smartcard-manager.c
+++ b/plugins/smartcard/gsd-smartcard-manager.c
@@ -190,7 +190,8 @@ watch_one_event_from_driver (GsdSmartcardManager       *self,
                                             operation,
                                             NULL);
 
-        card = SECMOD_WaitForAnyTokenEvent (operation->driver, 0, PR_SecondsToInterval (1));
+        if (handler_id != 0)
+                card = SECMOD_WaitForAnyTokenEvent (operation->driver, 0, PR_SecondsToInterval (1));
 
         g_cancellable_disconnect (cancellable, handler_id);
 
@@ -773,6 +774,8 @@ gsd_smartcard_manager_stop (GsdSmartcardManager *self)
 {
         g_debug ("Stopping smartcard manager");
 
+        g_cancellable_cancel (self->cancellable);
+
         unload_nss (self);
 
         g_clear_object (&self->settings);