diff options
| author |   John Keeping <john@metanate.com> | 2019-08-05 17:01:21 +0100 |
|---|---|---|
| committer |   Felipe Balbi <felipe.balbi@linux.intel.com> | 2019-08-09 08:28:29 +0300 |
| commit | 37bea42fec575203c1b49d64322f717c29e82b90 (patch) | |
| tree | 01b4da426a3b2153f0fd6c7065c218476d15c667 /drivers/usb/dwc2 | |
| parent | usb: gadget: atmel_usba_udc: Mark expected switch fall-through (diff) | |
| download | linux-dev-37bea42fec575203c1b49d64322f717c29e82b90.tar.xz linux-dev-37bea42fec575203c1b49d64322f717c29e82b90.zip | |
usb: dwc2: gadget: Fix kill_all_requests race
When a gadget is disabled, kill_all_requests() can be called
simultaneously from both a user process via dwc2_hsotg_pullup() and from
the interrupt handler if the hardware detects disconnection.
Since we drop the lock in dwc2_hsotg_complete_request() in order to call
the completion handler, this means that the list is modified
concurrently and leads to an infinite loop in kill_all_requests().
Replace the foreach loop with a while-not-empty loop in order to remove
the danger of this concurrent modification.
Note: I observed this with threadirqs, I'm not sure if it can be
triggered without threaded interrupts.
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/dwc2')
| -rw-r--r-- | drivers/usb/dwc2/gadget.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index bff48a8a1984..6be10e496e10 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -3224,14 +3224,15 @@ static void kill_all_requests(struct dwc2_hsotg *hsotg, struct dwc2_hsotg_ep *ep, int result) { - struct dwc2_hsotg_req *req, *treq; unsigned int size; ep->req = NULL; - list_for_each_entry_safe(req, treq, &ep->queue, queue) - dwc2_hsotg_complete_request(hsotg, ep, req, - result); + while (!list_empty(&ep->queue)) { + struct dwc2_hsotg_req *req = get_ep_head(ep); + + dwc2_hsotg_complete_request(hsotg, ep, req, result); + } if (!hsotg->dedicated_fifos) return; |