From 96bd39df29c29d348d65311e5954c0b7d3a2a790 Mon Sep 17 00:00:00 2001 From: Mayank Rana Date: Fri, 23 Mar 2018 10:05:33 -0700 Subject: [PATCH] usb: dwc3: gadget: Fix list_del corruption in dwc3_ep_dequeue dwc3_ep_dequeue() waits for completion of End Transfer command using wait_event_lock_irq(), which will release the dwc3->lock while waiting and reacquire after completion. This allows a potential race condition with ep_disable() which also removes all requests from started_list and pending_list. The check for NULL r->trb should catch this but currently it exits to the wrong 'out1' label which calls dwc3_gadget_giveback(). Since its list entry was already removed, if CONFIG_DEBUG_LIST is enabled a 'list_del corruption' bug is thrown since its next/prev pointers are already LIST_POISON1/2. If r->trb is NULL it should simply exit to 'out0'. Fixes: cf3113d893d4 ("usb: dwc3: gadget: properly increment dequeue pointer on ep_dequeue") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Mayank Rana Signed-off-by: Jack Pham Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 206ecc7428da..0dedf8a799f4 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1424,7 +1424,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, dwc->lock); if (!r->trb) - goto out1; + goto out0; if (r->num_pending_sgs) { struct dwc3_trb *trb;