Patch "can: c_can: c_can_handle_bus_err(): update statistics if skb allocation fails" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    can: c_can: c_can_handle_bus_err(): update statistics if skb allocation fails

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     can-c_can-c_can_handle_bus_err-update-statistics-if-.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b326aa76d1d11c1df4365de1f1174262c5f655c3
Author: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
Date:   Fri Nov 22 23:15:42 2024 +0100

    can: c_can: c_can_handle_bus_err(): update statistics if skb allocation fails
    
    [ Upstream commit 9e66242504f49e17481d8e197730faba7d99c934 ]
    
    Ensure that the statistics are always updated, even if the skb
    allocation fails.
    
    Fixes: 4d6d26537940 ("can: c_can: fix {rx,tx}_errors statistics")
    Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
    Link: https://patch.msgid.link/20241122221650.633981-2-dario.binacchi@xxxxxxxxxxxxxxxxxxxx
    Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/can/c_can/c_can_main.c b/drivers/net/can/c_can/c_can_main.c
index d9595eb3e125f..875ac76bc5fdd 100644
--- a/drivers/net/can/c_can/c_can_main.c
+++ b/drivers/net/can/c_can/c_can_main.c
@@ -1022,49 +1022,57 @@ static int c_can_handle_bus_err(struct net_device *dev,
 
 	/* propagate the error condition to the CAN stack */
 	skb = alloc_can_err_skb(dev, &cf);
-	if (unlikely(!skb))
-		return 0;
 
 	/* check for 'last error code' which tells us the
 	 * type of the last error to occur on the CAN bus
 	 */
-	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+	if (likely(skb))
+		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 
 	switch (lec_type) {
 	case LEC_STUFF_ERROR:
 		netdev_dbg(dev, "stuff error\n");
-		cf->data[2] |= CAN_ERR_PROT_STUFF;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
 		stats->rx_errors++;
 		break;
 	case LEC_FORM_ERROR:
 		netdev_dbg(dev, "form error\n");
-		cf->data[2] |= CAN_ERR_PROT_FORM;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_FORM;
 		stats->rx_errors++;
 		break;
 	case LEC_ACK_ERROR:
 		netdev_dbg(dev, "ack error\n");
-		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 		stats->tx_errors++;
 		break;
 	case LEC_BIT1_ERROR:
 		netdev_dbg(dev, "bit1 error\n");
-		cf->data[2] |= CAN_ERR_PROT_BIT1;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT1;
 		stats->tx_errors++;
 		break;
 	case LEC_BIT0_ERROR:
 		netdev_dbg(dev, "bit0 error\n");
-		cf->data[2] |= CAN_ERR_PROT_BIT0;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT0;
 		stats->tx_errors++;
 		break;
 	case LEC_CRC_ERROR:
 		netdev_dbg(dev, "CRC error\n");
-		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 		stats->rx_errors++;
 		break;
 	default:
 		break;
 	}
 
+	if (unlikely(!skb))
+		return 0;
+
 	netif_receive_skb(skb);
 	return 1;
 }