The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 94cddf1e9227a171b27292509d59691819c458db Mon Sep 17 00:00:00 2001
From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
Date: Tue, 23 Nov 2021 20:16:54 +0900
Subject: [PATCH] can: pch_can: pch_can_rx_normal: fix use after free
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>
diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 92a54a5fd4c5..964c8a09226a 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->len;
+ netif_receive_skb(skb);
pch_fifo_thresh(priv, obj_num);
obj_num++;
