can: m_can: m_can_tx_handler(): fix use after free of skb

commit 2e8e79c416aae1de224c0f1860f2e3350fa171f8 upstream.

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.

Fixes: 80646733f1 ("can: m_can: update to support CAN FD features")
Link: https://lore.kernel.org/all/20220317081305.739554-1-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Reported-by: Hangyu Hua <hbh25y@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marc Kleine-Budde 2022-03-17 08:57:35 +01:00 committed by Greg Kroah-Hartman
parent 579c8a2e63
commit 08d90846e4

View File

@ -1443,8 +1443,6 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
M_CAN_FIFO_DATA(i / 4),
*(u32 *)(cf->data + i));
can_put_echo_skb(skb, dev, 0);
if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
cccr = m_can_read(cdev, M_CAN_CCCR);
cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
@ -1461,6 +1459,9 @@ 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);
m_can_write(cdev, M_CAN_TXBAR, 0x1);
/* End of xmit function for version 3.0.x */
} else {