del_timer() does not wait for a possible running callback to
complete. So the call side might free request and the associated
objects while on another cpu the timer handler runs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: s390 <linux-s390@vger.kernel.org>
---
 drivers/s390/char/tape_std.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: tip/drivers/s390/char/tape_std.c
===================================================================
--- tip.orig/drivers/s390/char/tape_std.c
+++ tip/drivers/s390/char/tape_std.c
@@ -78,7 +78,7 @@ tape_std_assign(struct tape_device *devi
 
 	rc = tape_do_io_interruptible(device, request);
 
-	del_timer(&timeout);
+	del_timer_sync(&timeout);
 
 	if (rc != 0) {
 		DBF_EVENT(3, "%08x: assign failed - device might be busy\n",