[ 3.5.y.z extended stable ] Patch "wusbcore: fix kernel panic when disconnecting a wireless" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    wusbcore: fix kernel panic when disconnecting a wireless

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From a1c60e6da84753d7e1faaa677e4603baea85ab31 Mon Sep 17 00:00:00 2001
From: Thomas Pugliese <thomas.pugliese at gmail.com>
Date: Fri, 9 Aug 2013 09:52:13 -0500
Subject: [PATCH] wusbcore: fix kernel panic when disconnecting a wireless
 USB->serial device

commit ec58fad1feb76c323ef47efff1d1e8660ed4644c upstream.

This patch fixes a kernel panic that can occur when disconnecting a
wireless USB->serial device.  When the serial device disconnects, the
device cleanup procedure ends up calling usb_hcd_disable_endpoint on the
serial device's endpoints.  The wusbcore uses the ABORT_RPIPE command to
abort all transfers on the given endpoint but it does not properly give
back the URBs when the transfer results return from the HWA.  This patch
prevents the transfer result processing code from bailing out when it sees
a WA_XFER_STATUS_ABORTED result code so that these urbs are flushed
properly by usb_hcd_disable_endpoint.  It also updates wa_urb_dequeue to
handle the case where the endpoint has already been cleaned up when
usb_kill_urb is called which is where the panic originally occurred.

Signed-off-by: Thomas Pugliese <thomas.pugliese at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/wusbcore/wa-xfer.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c
index 57c01ab..1ebc17e 100644
--- a/drivers/usb/wusbcore/wa-xfer.c
+++ b/drivers/usb/wusbcore/wa-xfer.c
@@ -1110,6 +1110,12 @@ int wa_urb_dequeue(struct wahc *wa, struct urb *urb)
 	}
 	spin_lock_irqsave(&xfer->lock, flags);
 	rpipe = xfer->ep->hcpriv;
+	if (rpipe == NULL) {
+		pr_debug("%s: xfer id 0x%08X has no RPIPE.  %s",
+			__func__, wa_xfer_id(xfer),
+			"Probably already aborted.\n" );
+		goto out_unlock;
+	}
 	/* Check the delayed list -> if there, release and complete */
 	spin_lock_irqsave(&wa->xfer_list_lock, flags2);
 	if (!list_empty(&xfer->list_node) && xfer->seg == NULL)
@@ -1493,8 +1499,7 @@ static void wa_xfer_result_cb(struct urb *urb)
 			break;
 		}
 		usb_status = xfer_result->bTransferStatus & 0x3f;
-		if (usb_status == WA_XFER_STATUS_ABORTED
-		    || usb_status == WA_XFER_STATUS_NOT_FOUND)
+		if (usb_status == WA_XFER_STATUS_NOT_FOUND)
 			/* taken care of already */
 			break;
 		xfer_id = xfer_result->dwTransferID;
--
1.8.3.2