usb: dwc3: gadget: fix race when disabling ep with cancelled xfers

[ Upstream commit d8eca64eec7103ab1fbabc0a187dbf6acfb2af93 ]

When disabling an endpoint which has cancelled requests, we should
make sure to giveback requests that are currently pending in the
cancelled list, otherwise we may fall into a situation where command
completion interrupt fires after endpoint has been disabled, therefore
causing a splat.

Fixes: fec9095bdef4 "usb: dwc3: gadget: remove wait_end_transfer"
Reported-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Link: https://lore.kernel.org/r/20191031090713.1452818-1-felipe.balbi@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 173f5329d3d9ebed82b74b18f8cd789938b3630e..56bd6ae0c18f9dc83ca097ea8541dbd62e1f9768 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -707,6 +707,12 @@ static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep)
 
                dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
        }
+
+       while (!list_empty(&dep->cancelled_list)) {
+               req = next_request(&dep->cancelled_list);
+
+               dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
+       }
 }
 
 /**