usb: dwc3: gadget: Stop processing more requests on IMI

When servicing a transfer completion event, the dwc3 driver will reclaim
TRBs of started requests up to the request associated with the interrupt
event. Currently we don't check for interrupt due to missed isoc, and
the driver may attempt to reclaim TRBs beyond the associated event. This
causes invalid memory access when the hardware still owns the TRB. If
there's a missed isoc TRB with IMI (interrupt on missed isoc), make sure
to stop servicing further.

Note that only the last TRB of chained TRBs has its status updated with
missed isoc.

Fixes: 72246da ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: [email protected]
Reported-by: Jeff Vanhoof <[email protected]>
Reported-by: Dan Vacura <[email protected]>
Signed-off-by: Thinh Nguyen <[email protected]>
Reviewed-by: Jeff Vanhoof <[email protected]>
Tested-by: Jeff Vanhoof <[email protected]>
Link: https://lore.kernel.org/r/b29acbeab531b666095dfdafd8cb5c7654fbb3e1.1666735451.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Thinh Nguyen

drivers/usb/dwc3/gadget.c

@@ -3248,6 +3248,10 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
 	if (event->status & DEPEVT_STATUS_SHORT && !chain)
 		return 1;
 
+	if ((trb->ctrl & DWC3_TRB_CTRL_ISP_IMI) &&
+	    DWC3_TRB_SIZE_TRBSTS(trb->size) == DWC3_TRBSTS_MISSED_ISOC)
+		return 1;
+
 	if ((trb->ctrl & DWC3_TRB_CTRL_IOC) ||
 	    (trb->ctrl & DWC3_TRB_CTRL_LST))
 		return 1;