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 10:47:48 +0000 (11:47 +0100)
commitac48ef15826e83f4206c47add61072e8fc76d328
treec223d55c5779a5eefff2c5ea9624c5f604025ed3
parent391187744436ec5bf00bab9952d145fc9fb652d1
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