[PATCH] Fix a deadlock in usbtest

ctrl_complete functions acquires ctx->lock and tries to unlink
all queued urbs in case of errors through usb_unlink_urb func.
In its turn usb_unlink_urb calls, through the hcd driver,
usb_hcd_giveback_urb which calls ctrl_complete again. At this
time, ctx->lock is already taken by the same function.

Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index ccc5e8238bd8..b42ae6bfb12b 100644
--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -802,7 +802,9 @@ error:
 
                                 if (u == urb || !u->dev)
                                         continue;
+                                spin_unlock(&ctx->lock);
                                 status = usb_unlink_urb (u);
+                                spin_lock(&ctx->lock);
                                 switch (status) {
                                 case -EINPROGRESS:
                                 case -EBUSY: