On Mon, Apr 04, 2022 at 09:08:30PM +0200, Marc Kleine-Budde wrote:
> 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: 80646733f11c ("can: m_can: update to support CAN FD features")
> Link: https://lore.kernel.org/all/20220317081305.739554-1-mkl@xxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> ---
> Hello Greg, hello Sasha,
>
> This is
>
> | 2e8e79c416aa can: m_can: m_can_tx_handler(): fix use after free of skb
>
> ported to v5.10.109.
>
> regards,
> Marc
>
> drivers/net/can/m_can/m_can.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 19a7e4adb933..52386460fe92 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -1491,8 +1491,6 @@ 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);
> @@ -1509,6 +1507,9 @@ 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);
You didn't build this patch :(
I'll go fix this by hand...
greg k-h
