[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>

diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index ccc5e8238bd889581b2b445cdb4b26108b5c6644..b42ae6bfb12bcf4fb863483b37c6e42c378160da 100644 (file)
--- 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: