This is a note to let you know that I've just added the patch titled
can: pch_can: pch_can_rx_normal: fix use after free
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-pch_can-pch_can_rx_normal-fix-use-after-free.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>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: can: pch_can: pch_can_rx_normal: fix use after free
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/can/pch_can.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -703,11 +703,11 @@ static int pch_can_rx_normal(struct net_
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++;
Patches currently in stable-queue which might be from mailhol.vincent@xxxxxxxxxx are
queue-4.4/can-pch_can-pch_can_rx_normal-fix-use-after-free.patch
