Commit 5063262b authored by Marc Kleine-Budde's avatar Marc Kleine-Budde Committed by Xiangwei Li
Browse files

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

stable inclusion
from stable-v4.19.253
commit 7728d937ec403a1ceff9483023252d2cb8777f81
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP6AL
CVE: CVE-2022-49275

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7728d937ec403a1ceff9483023252d2cb8777f81

--------------------------------

commit 2e8e79c4 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: 80646733 ("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: default avatarHangyu Hua <hbh25y@gmail.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
[sudip: adjust context]
Signed-off-by: default avatarSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarXiangwei Li <liwei728@huawei.com>
parent 3c67b39e

drivers/net/can/m_can/m_can.c

+3 −2
Original line number Diff line number Diff line
@@ -1443,8 +1443,6 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, 
					 M_CAN_FIFO_DATA(i / 4),

					 *(u32 *)(cf->data + i));



		can_put_echo_skb(skb, dev, 0);



		if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {

			cccr = m_can_read(priv, M_CAN_CCCR);

			cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
@@ -1461,6 +1459,9 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, 
			m_can_write(priv, M_CAN_CCCR, cccr);

		}

		m_can_write(priv, M_CAN_TXBTIE, 0x1);



		can_put_echo_skb(skb, dev, 0);



		m_can_write(priv, M_CAN_TXBAR, 0x1);

		/* End of xmit function for version 3.0.x */

	} else {