6.6-stable review patch. If anyone has any objections, please let me know.
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From: Marc Kleine-Budde mkl@pengutronix.de
[ Upstream commit 395d988f93861101ec89d0dd9e3b876ae9392a5b ]
The URB received in gs_usb_receive_bulk_callback() contains a struct gs_host_frame. The length of the data after the header depends on the gs_host_frame hf::flags and the active device features (e.g. time stamping).
Introduce a new function gs_usb_get_minimum_length() and check that we have at least received the required amount of data before accessing it. Only copy the data to that skb that has actually been received.
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices") Link: https://patch.msgid.link/20251114-gs_usb-fix-usb-callbacks-v1-3-a29b42eacada... [mkl: rename gs_usb_get_minimum_length() -> +gs_usb_get_minimum_rx_length()] Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/can/usb/gs_usb.c | 59 +++++++++++++++++++++++++++++++++--- 1 file changed, 54 insertions(+), 5 deletions(-)
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index e786616d167b8..72997312c9567 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -258,6 +258,11 @@ struct canfd_quirk { u8 quirk; } __packed;
+/* struct gs_host_frame::echo_id == GS_HOST_FRAME_ECHO_ID_RX indicates + * a regular RX'ed CAN frame + */ +#define GS_HOST_FRAME_ECHO_ID_RX 0xffffffff + struct gs_host_frame { struct_group(header, u32 echo_id; @@ -567,6 +572,37 @@ gs_usb_get_echo_skb(struct gs_can *dev, struct sk_buff *skb, return len; }
+static unsigned int +gs_usb_get_minimum_rx_length(const struct gs_can *dev, const struct gs_host_frame *hf, + unsigned int *data_length_p) +{ + unsigned int minimum_length, data_length = 0; + + if (hf->flags & GS_CAN_FLAG_FD) { + if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX) + data_length = can_fd_dlc2len(hf->can_dlc); + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + /* timestamp follows data field of max size */ + minimum_length = struct_size(hf, canfd_ts, 1); + else + minimum_length = sizeof(hf->header) + data_length; + } else { + if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX && + !(hf->can_id & cpu_to_le32(CAN_RTR_FLAG))) + data_length = can_cc_dlc2len(hf->can_dlc); + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + /* timestamp follows data field of max size */ + minimum_length = struct_size(hf, classic_can_ts, 1); + else + minimum_length = sizeof(hf->header) + data_length; + } + + *data_length_p = data_length; + return minimum_length; +} + static void gs_usb_receive_bulk_callback(struct urb *urb) { struct gs_usb *parent = urb->context; @@ -575,7 +611,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) int rc; struct net_device_stats *stats; struct gs_host_frame *hf = urb->transfer_buffer; - unsigned int minimum_length; + unsigned int minimum_length, data_length; struct gs_tx_context *txc; struct can_frame *cf; struct canfd_frame *cfd; @@ -618,20 +654,33 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) if (!netif_running(netdev)) goto resubmit_urb;
- if (hf->echo_id == -1) { /* normal rx */ + minimum_length = gs_usb_get_minimum_rx_length(dev, hf, &data_length); + if (urb->actual_length < minimum_length) { + stats->rx_errors++; + stats->rx_length_errors++; + + if (net_ratelimit()) + netdev_err(netdev, + "short read (actual_length=%u, minimum_length=%u)\n", + urb->actual_length, minimum_length); + + goto resubmit_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) return;
cfd->can_id = le32_to_cpu(hf->can_id); - cfd->len = can_fd_dlc2len(hf->can_dlc); + cfd->len = data_length; if (hf->flags & GS_CAN_FLAG_BRS) cfd->flags |= CANFD_BRS; if (hf->flags & GS_CAN_FLAG_ESI) cfd->flags |= CANFD_ESI;
- memcpy(cfd->data, hf->canfd->data, cfd->len); + memcpy(cfd->data, hf->canfd->data, data_length); } else { skb = alloc_can_skb(netdev, &cf); if (!skb) @@ -640,7 +689,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) cf->can_id = le32_to_cpu(hf->can_id); can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
- memcpy(cf->data, hf->classic_can->data, 8); + memcpy(cf->data, hf->classic_can->data, data_length);
/* ERROR frames tell us information about the controller */ if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)