From: Konstantin Khlebnikov <khlebnikov@openvz.org>
Date: Fri, 14 Dec 2012 01:02:36 +0000 (+0000)
Subject: mISDN: fix race in timer canceling on module unloading
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4a0ae7b0a9e55db9b85f8abda623f145311eb951;p=openwrt%2Fstaging%2Fblogic.git

mISDN: fix race in timer canceling on module unloading

Using timer_pending() without additional syncronization is racy,
del_timer_sync() must be used here for waiting in-flight handler.
Bug caught with help from "debug-objects" during random insmod/rmmod.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/isdn/mISDN/dsp_core.c b/drivers/isdn/mISDN/dsp_core.c
index 28c99c623bcd..22b720ec80cb 100644
--- a/drivers/isdn/mISDN/dsp_core.c
+++ b/drivers/isdn/mISDN/dsp_core.c
@@ -1217,8 +1217,7 @@ static void __exit dsp_cleanup(void)
 {
 	mISDN_unregister_Bprotocol(&DSP);
 
-	if (timer_pending(&dsp_spl_tl))
-		del_timer(&dsp_spl_tl);
+	del_timer_sync(&dsp_spl_tl);
 
 	if (!list_empty(&dsp_ilist)) {
 		printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "