[34-longterm 127/247] staging: usbip: vhci: refuse to enqueue for dead connections

From: Paul Gortmaker
Date: Thu Jun 23 2011 - 14:10:51 EST


From: Max Vozeler <max@xxxxxxxxxxx>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit 6d212153a838354078cc7d96f9bb23b7d1fd3d1b upstream.

There can be requests to enqueue URBs while we are shutting
down a connection.

Signed-off-by: Max Vozeler <max@xxxxxxxxxxx>
Tested-by: Mark Wehby <MWehby@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
drivers/staging/usbip/vhci_hcd.c | 15 +++++++++++++--
1 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/usbip/vhci_hcd.c b/drivers/staging/usbip/vhci_hcd.c
index 9878e5d..006d5f7 100644
--- a/drivers/staging/usbip/vhci_hcd.c
+++ b/drivers/staging/usbip/vhci_hcd.c
@@ -559,6 +559,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
struct device *dev = &urb->dev->dev;
int ret = 0;
unsigned long flags;
+ struct vhci_device *vdev;

usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
hcd, urb, mem_flags);
@@ -574,6 +575,18 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
return urb->status;
}

+ vdev = port_to_vdev(the_controller->pending_port);
+
+ /* refuse enqueue for dead connection */
+ spin_lock(&vdev->ud.lock);
+ if (vdev->ud.status == VDEV_ST_NULL || vdev->ud.status == VDEV_ST_ERROR) {
+ usbip_uerr("enqueue for inactive port %d\n", vdev->rhport);
+ spin_unlock(&vdev->ud.lock);
+ spin_unlock_irqrestore(&the_controller->lock, flags);
+ return -ENODEV;
+ }
+ spin_unlock(&vdev->ud.lock);
+
ret = usb_hcd_link_urb_to_ep(hcd, urb);
if (ret)
goto no_need_unlink;
@@ -592,8 +605,6 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
__u8 type = usb_pipetype(urb->pipe);
struct usb_ctrlrequest *ctrlreq =
(struct usb_ctrlrequest *) urb->setup_packet;
- struct vhci_device *vdev =
- port_to_vdev(the_controller->pending_port);

if (type != PIPE_CONTROL || !ctrlreq) {
dev_err(dev, "invalid request to devnum 0\n");
--
1.7.4.4

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