Upstream patch/fix that was included in the next release of pcsclite:
https://anonscm.debian.org/cgit/pcsclite/PCSC.git/patch/?id=697fe05967af7ea215bcd5d5774be587780c9e22
patch by Peter Wu <[email protected]> 2016-12-25 22:31:24 (GMT)
committed by Ludovic Rousseau <[email protected]> 2016-12-30 16:18:39 (GMT)

Once MSGRemoveContext is invoked (via SCARD_RELEASE_CONTEXT), cardsList is freed. 
A repeated invocation of SCARD_RELEASE_CONTEXT (with an empty context handle) 
results in a use-after-free followed by a double-free. After MSGRemoveContext, 
invocation of SCardEstablishContext enable further use-after-free of cardsList in 
MSGCheckHandleAssociation, MSGRemoveContext, MSGAddHandle, MSGRemoveHandle. 

To avoid this problem, destroy the list only when the client connection is terminated.

This patch was based on the above and modified to work with our v1.8.14 of the pcsc-lite source code 
and named accordingly to build with our existing Solaris pcsc-lite userland patch layout.

--- a/src/winscard_svc.c	2017-01-09 14:27:56.897972773 -0500
+++ b/src/winscard_svc.c	2017-01-09 14:26:46.043849006 -0500
@@ -868,7 +868,6 @@
 		UNREF_READER(rContext)
 	}
 	(void)pthread_mutex_unlock(&threadContext->cardsList_lock);
-	list_destroy(&threadContext->cardsList);
 
 	/* We only mark the context as no longer in use.
 	 * The memory is freed in MSGCleanupCLient() */
@@ -979,6 +978,11 @@
 		(void)MSGRemoveContext(threadContext->hContext, threadContext);
 	}
 
+       
+	(void)pthread_mutex_lock(&threadContext->cardsList_lock);
+	list_destroy(&threadContext->cardsList);
+	(void)pthread_mutex_unlock(&threadContext->cardsList_lock);
+
 	Log3(PCSC_LOG_DEBUG,
 		"Thread is stopping: dwClientID=%d, threadContext @%p",
 		threadContext->dwClientID, threadContext);