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@pengutronix.de Cc: stable@vger.kernel.org Reported-by: Hangyu Hua hbh25y@gmail.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- 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); + m_can_write(cdev, M_CAN_TXBAR, 0x1); /* End of xmit function for version 3.0.x */ } else {