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)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Wed, 20 Jan 2021 12:32:05 +0000 (13:32 +0100)
commit03f16c5075b22c8902d2af739969e878b0879c94
tree9e9609f281b8ed7468d8e883915c2e528f75ff28
parent9c30ae8398b0813e237bde387d67a7f74ab2db2d
can: dev: can_restart: fix use after free bug

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>
drivers/net/can/dev.c