From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
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@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
[mkl: backport to v5.10]
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
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 --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++;
--
2.33.0
