Patch "usb: misc: usbtest: add fix for driver hang" has been added to the 4.4-stable tree

Patch "usb: misc: usbtest: add fix for driver hang" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    usb: misc: usbtest: add fix for driver hang

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-misc-usbtest-add-fix-for-driver-hang.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 539587511835ea12d8daa444cbed766cf2bc3612 Mon Sep 17 00:00:00 2001
From: Lu Baolu <baolu.lu@linux.intel.com>
Date: Thu, 11 Aug 2016 10:31:14 +0800
Subject: usb: misc: usbtest: add fix for driver hang

From: Lu Baolu <baolu.lu@linux.intel.com>

commit 539587511835ea12d8daa444cbed766cf2bc3612 upstream.

In sg_timeout(), req->status is set to "-ETIMEDOUT" before calling
into usb_sg_cancel(). usb_sg_cancel() will do nothing and return
directly if req->status has been set to a non-zero value. This will
cause driver hang whenever transfer time out is triggered.

This patch fixes this issue. It could be backported to stable kernel
with version later than v3.15.

Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/misc/usbtest.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -558,7 +558,6 @@ static void sg_timeout(unsigned long _re
 {
 	struct usb_sg_request	*req = (struct usb_sg_request *) _req;
 
-	req->status = -ETIMEDOUT;
 	usb_sg_cancel(req);
 }
 
@@ -589,8 +588,10 @@ static int perform_sglist(
 		mod_timer(&sg_timer, jiffies +
 				msecs_to_jiffies(SIMPLE_IO_TIMEOUT));
 		usb_sg_wait(req);
-		del_timer_sync(&sg_timer);
-		retval = req->status;
+		if (!del_timer_sync(&sg_timer))
+			retval = -ETIMEDOUT;
+		else
+			retval = req->status;
 
 		/* FIXME check resulting data pattern */
 


Patches currently in stable-queue which might be from baolu.lu@linux.intel.com are

queue-4.4/usb-misc-usbtest-add-fix-for-driver-hang.patch