4.16-stable review patch. If anyone has any objections, please let me know.
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From: Mayank Rana mrana@codeaurora.org
commit 96bd39df29c29d348d65311e5954c0b7d3a2a790 upstream.
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 mrana@codeaurora.org Signed-off-by: Jack Pham jackp@codeaurora.org Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/dwc3/gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1424,7 +1424,7 @@ static int dwc3_gadget_ep_dequeue(struct dwc->lock);
if (!r->trb) - goto out1; + goto out0;
if (r->num_pending_sgs) { struct dwc3_trb *trb;