can: dev: can_restart: fix use after free bug
authorVincent Mailhol <mailhol.vincent@wanadoo.fr>
Wed, 20 Jan 2021 11:41:35 +0000 (20:41 +0900)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 27 Jan 2021 10:55:10 +0000 (11:55 +0100)
commit593c072b7b3c4d7044416eb039d9ad706bedd67a
treee0e0b4edc7a6f764059db93c9a92509abdfec7df
parent66ee6d91d3275832a0722f3ea53e7ee99911e691
can: dev: can_restart: fix use after free bug

[ Upstream commit 03f16c5075b22c8902d2af739969e878b0879c94 ]

After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the netif_rx_ni() in:
      stats->rx_bytes += cf->len;

Reordering the lines solves the issue.

Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/r/20210120114137.200019-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/can/dev.c