usb: gadget: mv_u3d_core: fix violation of locking discipline in mv_u3d_ep_disable()

mv_u3d_nuke() expects to be calles with ep->u3d->lock held,
because mv_u3d_done() does. But mv_u3d_ep_disable() calls it
without lock that can lead to unpleasant consequences.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/usb/gadget/mv_u3d_core.c b/drivers/usb/gadget/mv_u3d_core.c
index bbb6e98c4384..561b30efb8ee 100644
--- a/drivers/usb/gadget/mv_u3d_core.c
+++ b/drivers/usb/gadget/mv_u3d_core.c
@@ -645,6 +645,7 @@ static int  mv_u3d_ep_disable(struct usb_ep *_ep)
         struct mv_u3d_ep *ep;
         struct mv_u3d_ep_context *ep_context;
         u32 epxcr, direction;
+        unsigned long flags;
 
         if (!_ep)
                 return -EINVAL;
@@ -661,7 +662,9 @@ static int  mv_u3d_ep_disable(struct usb_ep *_ep)
         direction = mv_u3d_ep_dir(ep);
 
         /* nuke all pending requests (does flush) */
+        spin_lock_irqsave(&u3d->lock, flags);
         mv_u3d_nuke(ep, -ESHUTDOWN);
+        spin_unlock_irqrestore(&u3d->lock, flags);
 
         /* Disable the endpoint for Rx or Tx and reset the endpoint type */
         if (direction == MV_U3D_EP_DIR_OUT) {