[PATCH 5.4 11/18] can: gs_usb: gs_can_start_xmit(): zero-initialize hf->{flags,reserved}

From: Greg Kroah-Hartman
Date: Fri Jan 14 2022 - 03:17:47 EST


From: Brian Silverman <brian.silverman@xxxxxxxxxxxxxxxxx>

commit 89d58aebe14a365c25ba6645414afdbf4e41cea4 upstream.

No information is deliberately sent in hf->flags in host -> device
communications, but the open-source candleLight firmware echoes it
back, which can result in the GS_CAN_FLAG_OVERFLOW flag being set and
generating spurious ERRORFRAMEs.

While there also initialize the reserved member with 0.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20220106002952.25883-1-brian.silverman@xxxxxxxxxxxxxxxxx
Link: https://github.com/candle-usb/candleLight_fw/issues/87
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Brian Silverman <brian.silverman@xxxxxxxxxxxxxxxxx>
[mkl: initialize the reserved member, too]
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/can/usb/gs_usb.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -507,6 +507,8 @@ static netdev_tx_t gs_can_start_xmit(str

hf->echo_id = idx;
hf->channel = dev->channel;
+ hf->flags = 0;
+ hf->reserved = 0;

cf = (struct can_frame *)skb->data;