Index: uspace/lib/libdrv/generic/driver.c
===================================================================
--- uspace/lib/libdrv/generic/driver.c	(revision 7f8b5815070a70217f19184d31a4e8837c21346f)
+++ uspace/lib/libdrv/generic/driver.c	(revision 2300b9d16356af1c2c6e7ca022000eaa4cff16d8)
@@ -81,8 +81,10 @@
 
 static void driver_irq_handler(ipc_callid_t iid, ipc_call_t *icall)
-{
+{	
 	int id = (int)IPC_GET_METHOD(*icall);
 	interrupt_context_t *ctx = find_interrupt_context_by_id(&interrupt_contexts, id);
-	(*ctx->handler)(ctx->dev, iid, icall);	
+	if (NULL != ctx && NULL != ctx->handler) {
+		(*ctx->handler)(ctx->dev, iid, icall);		
+	}
 }