Merge tag 'linux-can-fixes-for-6.18-20251126' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2025-11-26

this is a pull request of 8 patches for net/main.

Seungjin Bae provides a patch for the kvaser_usb driver to fix a
potential infinite loop in the USB data stream command parser.

Thomas Mühlbacher's patch for the sja1000 driver IRQ handler's max
loop handling, that might lead to unhandled interrupts.

3 patches by me for the gs_usb driver fix handling of failed transmit
URBs and add checking of the actual length of received URBs before
accessing the data.

The next patch is by me and is a port of Thomas Mühlbacher's patch
(fix IRQ handler's max loop handling, that might lead to unhandled
interrupts.) to the sun4i_can driver.

Biju Das provides a patch for the rcar_canfd driver to fix the CAN-FD
mode setting.

The last patch is by Shaurya Rane for the em_canid filter to ensure
that the complete CAN frame is present in the linear data buffer
before accessing it.

* tag 'linux-can-fixes-for-6.18-20251126' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  net/sched: em_canid: fix uninit-value in em_canid_match
  can: rcar_canfd: Fix CAN-FD mode as default
  can: sun4i_can: sun4i_can_interrupt(): fix max irq loop handling
  can: gs_usb: gs_usb_receive_bulk_callback(): check actual_length before accessing data
  can: gs_usb: gs_usb_receive_bulk_callback(): check actual_length before accessing header
  can: gs_usb: gs_usb_xmit_callback(): fix handling of failed transmitted URBs
  can: sja1000: fix max irq loop handling
  can: kvaser_usb: leaf: Fix potential infinite loop in command parsers
====================

Link: https://patch.msgid.link/20251126155713.217105-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/can/rcar/rcar_canfd.c

@@ -709,6 +709,11 @@ static void rcar_canfd_set_bit_reg(void __iomem *addr, u32 val)
 	rcar_canfd_update(val, val, addr);
 }
 
+static void rcar_canfd_clear_bit_reg(void __iomem *addr, u32 val)
+{
+	rcar_canfd_update(val, 0, addr);
+}
+
 static void rcar_canfd_update_bit_reg(void __iomem *addr, u32 mask, u32 val)
 {
 	rcar_canfd_update(mask, val, addr);
@@ -755,25 +760,6 @@ static void rcar_canfd_set_rnc(struct rcar_canfd_global *gpriv, unsigned int ch,
 	rcar_canfd_set_bit(gpriv->base, RCANFD_GAFLCFG(w), rnc);
 }
 
-static void rcar_canfd_set_mode(struct rcar_canfd_global *gpriv)
-{
-	if (gpriv->info->ch_interface_mode) {
-		u32 ch, val = gpriv->fdmode ? RCANFD_GEN4_FDCFG_FDOE
-					    : RCANFD_GEN4_FDCFG_CLOE;
-
-		for_each_set_bit(ch, &gpriv->channels_mask,
-				 gpriv->info->max_channels)
-			rcar_canfd_set_bit_reg(&gpriv->fcbase[ch].cfdcfg, val);
-	} else {
-		if (gpriv->fdmode)
-			rcar_canfd_set_bit(gpriv->base, RCANFD_GRMCFG,
-					   RCANFD_GRMCFG_RCMC);
-		else
-			rcar_canfd_clear_bit(gpriv->base, RCANFD_GRMCFG,
-					     RCANFD_GRMCFG_RCMC);
-	}
-}
-
 static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 {
 	struct device *dev = &gpriv->pdev->dev;
@@ -806,6 +792,16 @@ static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 	/* Reset Global error flags */
 	rcar_canfd_write(gpriv->base, RCANFD_GERFL, 0x0);
 
+	/* Set the controller into appropriate mode */
+	if (!gpriv->info->ch_interface_mode) {
+		if (gpriv->fdmode)
+			rcar_canfd_set_bit(gpriv->base, RCANFD_GRMCFG,
+					   RCANFD_GRMCFG_RCMC);
+		else
+			rcar_canfd_clear_bit(gpriv->base, RCANFD_GRMCFG,
+					     RCANFD_GRMCFG_RCMC);
+	}
+
 	/* Transition all Channels to reset mode */
 	for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
 		rcar_canfd_clear_bit(gpriv->base,
@@ -823,10 +819,23 @@ static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 			dev_dbg(dev, "channel %u reset failed\n", ch);
 			return err;
 		}
-	}
 
 		/* Set the controller into appropriate mode */
-	rcar_canfd_set_mode(gpriv);
+		if (gpriv->info->ch_interface_mode) {
+			/* Do not set CLOE and FDOE simultaneously */
+			if (!gpriv->fdmode) {
+				rcar_canfd_clear_bit_reg(&gpriv->fcbase[ch].cfdcfg,
+							 RCANFD_GEN4_FDCFG_FDOE);
+				rcar_canfd_set_bit_reg(&gpriv->fcbase[ch].cfdcfg,
+						       RCANFD_GEN4_FDCFG_CLOE);
+			} else {
+				rcar_canfd_clear_bit_reg(&gpriv->fcbase[ch].cfdcfg,
+							 RCANFD_GEN4_FDCFG_FDOE);
+				rcar_canfd_clear_bit_reg(&gpriv->fcbase[ch].cfdcfg,
+							 RCANFD_GEN4_FDCFG_CLOE);
+			}
+		}
+	}
 
 	return 0;
 }

drivers/net/can/sja1000/sja1000.c

@@ -548,8 +548,8 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 	if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF)
 		goto out;
 
-	while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
-	       (n < SJA1000_MAX_IRQ)) {
+	while ((n < SJA1000_MAX_IRQ) &&
+	       (isrc = priv->read_reg(priv, SJA1000_IR))) {
 
 		status = priv->read_reg(priv, SJA1000_SR);
 		/* check for absent controller due to hw unplug */

drivers/net/can/sun4i_can.c

@@ -657,8 +657,8 @@ static irqreturn_t sun4i_can_interrupt(int irq, void *dev_id)
 	u8 isrc, status;
 	int n = 0;
 
-	while ((isrc = readl(priv->base + SUN4I_REG_INT_ADDR)) &&
-	       (n < SUN4I_CAN_MAX_IRQ)) {
+	while ((n < SUN4I_CAN_MAX_IRQ) &&
+	       (isrc = readl(priv->base + SUN4I_REG_INT_ADDR))) {
 		n++;
 		status = readl(priv->base + SUN4I_REG_STA_ADDR);
 

drivers/net/can/usb/gs_usb.c

@@ -261,7 +261,13 @@ 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;
 		__le32 can_id;
 
@@ -269,6 +275,7 @@ struct gs_host_frame {
 		u8 channel;
 		u8 flags;
 		u8 reserved;
+	);
 
 	union {
 		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
@@ -568,6 +575,37 @@ 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;
@@ -576,6 +614,7 @@ 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, data_length;
 	struct gs_tx_context *txc;
 	struct can_frame *cf;
 	struct canfd_frame *cfd;
@@ -594,6 +633,15 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 		return;
 	}
 
+	minimum_length = sizeof(hf->header);
+	if (urb->actual_length < minimum_length) {
+		dev_err_ratelimited(&parent->udev->dev,
+				    "short read (actual_length=%u, minimum_length=%u)\n",
+				    urb->actual_length, minimum_length);
+
+		goto resubmit_urb;
+	}
+
 	/* device reports out of range channel id */
 	if (hf->channel >= parent->channel_cnt)
 		goto device_detach;
@@ -609,20 +657,33 @@ 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)
@@ -631,7 +692,7 @@ 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)
@@ -687,7 +748,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 resubmit_urb:
 	usb_fill_bulk_urb(urb, parent->udev,
 			  parent->pipe_in,
-			  hf, dev->parent->hf_size_rx,
+			  hf, parent->hf_size_rx,
 			  gs_usb_receive_bulk_callback, parent);
 
 	rc = usb_submit_urb(urb, GFP_ATOMIC);
@@ -750,8 +811,21 @@ static void gs_usb_xmit_callback(struct urb *urb)
 	struct gs_can *dev = txc->dev;
 	struct net_device *netdev = dev->netdev;
 
-	if (urb->status)
-		netdev_info(netdev, "usb xmit fail %u\n", txc->echo_id);
+	if (!urb->status)
+		return;
+
+	if (urb->status != -ESHUTDOWN && net_ratelimit())
+		netdev_info(netdev, "failed to xmit URB %u: %pe\n",
+			    txc->echo_id, ERR_PTR(urb->status));
+
+	netdev->stats.tx_dropped++;
+	netdev->stats.tx_errors++;
+
+	can_free_echo_skb(netdev, txc->echo_id, NULL);
+	gs_free_tx_context(txc);
+	atomic_dec(&dev->active_tx_urbs);
+
+	netif_wake_queue(netdev);
 }
 
 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,

drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c

@@ -685,7 +685,7 @@ static int kvaser_usb_leaf_wait_cmd(const struct kvaser_usb *dev, u8 id,
 			 * for further details.
 			 */
 			if (tmp->len == 0) {
-				pos = round_up(pos,
+				pos = round_up(pos + 1,
 					       le16_to_cpu
 						(dev->bulk_in->wMaxPacketSize));
 				continue;
@@ -1732,7 +1732,7 @@ static void kvaser_usb_leaf_read_bulk_callback(struct kvaser_usb *dev,
 		 * number of events in case of a heavy rx load on the bus.
 		 */
 		if (cmd->len == 0) {
-			pos = round_up(pos, le16_to_cpu
+			pos = round_up(pos + 1, le16_to_cpu
 						(dev->bulk_in->wMaxPacketSize));
 			continue;
 		}

net/sched/em_canid.c

@@ -99,6 +99,9 @@ static int em_canid_match(struct sk_buff *skb, struct tcf_ematch *m,
 	int i;
 	const struct can_filter *lp;
 
+	if (!pskb_may_pull(skb, CAN_MTU))
+		return 0;
+
 	can_id = em_canid_get_id(skb);
 
 	if (can_id & CAN_EFF_FLAG) {