FAILED: patch "[PATCH] can: m_can: m_can_tx_handler(): fix use after free of skb" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2e8e79c416aae1de224c0f1860f2e3350fa171f8 Mon Sep 17 00:00:00 2001
From: Marc Kleine-Budde <[email protected]>
Date: Thu, 17 Mar 2022 08:57:35 +0100
Subject: [PATCH] can: m_can: m_can_tx_handler(): fix use after free of skb

can_put_echo_skb() will clone skb then free the skb. Move the can_put_echo_skb() for the m_can version 3.0.x directly before the start of the xmit in hardware, similar to the 3.1.x branch.

index 1a4b56f6fa8c..b3b5bc1c803b 100644
@@ -1637,8 +1637,6 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 		if (err)
 			goto out_fail;
 
-		can_put_echo_skb(skb, dev, 0, 0);
-
 		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
 			cccr = m_can_read(cdev, M_CAN_CCCR);
 			cccr &= ~CCCR_CMR_MASK;

@@ -1655,6 +1653,9 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 			m_can_write(cdev, M_CAN_CCCR, cccr);
 		}
 		m_can_write(cdev, M_CAN_TXBTIE, 0x1);
+
+		can_put_echo_skb(skb, dev, 0, 0);
+
 		m_can_write(cdev, M_CAN_TXBAR, 0x1);
 		/* End of xmit function for version 3.0.x */
 	} else {