The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 26288448120b28af1dfd85a6fa6b6d55a16c7f2f Mon Sep 17 00:00:00 2001

From: Albert Wang albertccwang@google.com Date: Tue, 9 Nov 2021 17:26:42 +0800 Subject: [PATCH] usb: dwc3: gadget: Fix null pointer exception

In the endpoint interrupt functions dwc3_gadget_endpoint_transfer_in_progress() and dwc3_gadget_endpoint_trbs_complete() will dereference the endpoint descriptor. But it could be cleared in __dwc3_gadget_ep_disable() when accessory disconnected. So we need to check whether it is null or not before dereferencing it.

Fixes: f09ddcfcb8c5 ("usb: dwc3: gadget: Prevent EP queuing while stopping transfers") Cc: stable stable@vger.kernel.org Reviewed-by: Jack Pham quic_jackp@quicinc.com Signed-off-by: Albert Wang albertccwang@google.com Link: https://lore.kernel.org/r/20211109092642.3507692-1-albertccwang@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index daa8f8548a2e..7e3db00e9759 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -3263,6 +3263,9 @@ static bool dwc3_gadget_endpoint_trbs_complete(struct dwc3_ep *dep, struct dwc3 *dwc = dep->dwc; bool no_started_trb = true;

+ if (!dep->endpoint.desc) + return no_started_trb; + dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);

if (dep->flags & DWC3_EP_END_TRANSFER_PENDING) @@ -3310,6 +3313,9 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep, { int status = 0;

+ if (!dep->endpoint.desc) + return; + if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) dwc3_gadget_endpoint_frame_from_event(dep, event);