4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mayank Rana <mrana@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx # v4.12+
Signed-off-by: Mayank Rana <mrana@xxxxxxxxxxxxxx>
Signed-off-by: Jack Pham <jackp@xxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
