2021-11-09 17:35:59

by Albert Wang

[permalink] [raw]
Subject: [PATCH v3] 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")
Reviewed-by: Jack Pham <[email protected]>
Signed-off-by: Albert Wang <[email protected]>
---
Changelog since v3:
- Put 'Signed-off-by' in the bottom line

Changelog since v2:
- Add 'Fixes' message
- Add 'Reviewed-by' message

Changelog since v1:
- Add null pointer check in dwc3_gadget_endpoint_trbs_complete()
- Add null pointer check in dwc3_gadget_endpoint_transfer_in_progress()

drivers/usb/dwc3/gadget.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 23de2a5a40d6..83c7344888fd 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3252,6 +3252,9 @@ 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)
@@ -3299,6 +3302,9 @@ 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);

--
2.34.0.rc0.344.g81b53c2807-goog