diff mbox series

can: pch_can: pch_can_rx_normal: fix use after free

Message ID 20211211212306.797338-1-mkl@pengutronix.de
State New
Headers show
Series can: pch_can: pch_can_rx_normal: fix use after free | expand

Commit Message

Marc Kleine-Budde Dec. 11, 2021, 9:23 p.m. UTC 
From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

commit 94cddf1e9227a171b27292509d59691819c458db 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: b21d18b51b31 ("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>
[mkl: backport to v5.10]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
Hey Greg,

this is the backport of
| 94cddf1e9227 ("can: pch_can: pch_can_rx_normal: fix use after free")
to v5.10

regards,
Marc

 drivers/net/can/pch_can.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 5c180d2f3c3c..79d9abdcc65a 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -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++;