can: pch_can: pch_can_rx_normal: fix use after free

commit 94cddf1e92 upstream.

After calling netif_receive_skb(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is dereferenced
just after the call netif_receive_skb(skb).

Reordering the lines solves the issue.

Fixes: b21d18b51b ("can: Topcliff: Add PCH_CAN driver.")
Link: https://lore.kernel.org/all/20211123111654.621610-1-mailhol.vincent@wanadoo.fr
Cc: stable@vger.kernel.org
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vincent Mailhol 2021-11-23 20:16:54 +09:00 committed by Greg Kroah-Hartman
parent 2737d0bc21
commit 703dde1120

View file

@ -692,11 +692,11 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
cf->data[i + 1] = data_reg >> 8;
}
netif_receive_skb(skb);
rcv_pkts++;
stats->rx_packets++;
quota--;
stats->rx_bytes += cf->can_dlc;
netif_receive_skb(skb);
pch_fifo_thresh(priv, obj_num);
obj_num++;