[PATCH can-next v5 4/6] can: gs_usb: gs_usb_receive_bulk_callback(): check for overflow flag if SKB allocation fails

[Marc Kleine-Budde]

If the allocation of an SKB fails in gs_usb_receive_bulk_callback(), the
function neither updates the statistics nor checks whether an overflow flag
is set in the host frame.

Instead of directly resubmitting the URB, first update the dropped RX
statistics then check if an overflow flag is set.

Closes: https://sashiko.dev/#/bug/linux-7b3fe6a0-4628-4d0e-aec0-69f4bf8ad5d4
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Fixes: 26949ac935e3 ("can: gs_usb: add CAN-FD support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
 drivers/net/can/usb/gs_usb.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 1527163e8c35..a42dba9d158e 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -673,8 +673,11 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 	if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX) { /* normal rx */
 		if (hf->flags & GS_CAN_FLAG_FD) {
 			skb = alloc_canfd_skb(netdev, &cfd);
-			if (!skb)
-				goto resubmit_urb;
+			if (!skb) {
+				stats->rx_dropped++;
+
+				goto check_overflow;
+			}
 
 			cfd->can_id = le32_to_cpu(hf->can_id);
 			cfd->len = data_length;
@@ -686,8 +689,11 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 			memcpy(cfd->data, hf->canfd->data, data_length);
 		} else {
 			skb = alloc_can_skb(netdev, &cf);
-			if (!skb)
-				goto resubmit_urb;
+			if (!skb) {
+				stats->rx_dropped++;
+
+				goto check_overflow;
+			}
 
 			cf->can_id = le32_to_cpu(hf->can_id);
 			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
@@ -728,6 +734,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 		netif_wake_queue(netdev);
 	}
 
+check_overflow:
 	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
 		stats->rx_over_errors++;
 		stats->rx_errors++;

-- 
2.53.0