2022-04-19 18:27:31

by Dragos-Marian Panait

Subject: [PATCH 5.4 0/1] can: usb_8dev: backport fix for CVE-2022-28388

The following commit is needed to fix CVE-2022-28388:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3d3925ff6433f98992685a9679613a2cc97f3ce2

Hangyu Hua (1):
can: usb_8dev: usb_8dev_start_xmit(): fix double dev_kfree_skb() in
error path

drivers/net/can/usb/usb_8dev.c | 30 ++++++++++++++----------------
1 file changed, 14 insertions(+), 16 deletions(-)


base-commit: e7f5213d755bc34f366d36f08825c0b446117d96
--
2.17.1

2022-04-19 20:56:29

by Dragos-Marian Panait

Subject: [PATCH 5.4 1/1] can: usb_8dev: usb_8dev_start_xmit(): fix double dev_kfree_skb() in error path

From: Hangyu Hua <[email protected]>

commit 3d3925ff6433f98992685a9679613a2cc97f3ce2 upstream.

There is no need to call dev_kfree_skb() when usb_submit_urb() fails
because can_put_echo_skb() deletes original skb and
can_free_echo_skb() deletes the cloned skb.

Fixes: 0024d8ad1639 ("can: usb_8dev: Add support for USB2CAN interface from 8 devices")
Link: https://lore.kernel.org/all/[email protected]
Cc: [email protected]
Signed-off-by: Hangyu Hua <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>
[DP: adjusted params of can_free_echo_skb() for 5.4 stable]
Signed-off-by: Dragos-Marian Panait <[email protected]>
---
drivers/net/can/usb/usb_8dev.c | 30 ++++++++++++++----------------
1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index c43e98bb6e2d..b514b2eaa318 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -670,9 +670,20 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
atomic_inc(&priv->active_tx_urbs);

err = usb_submit_urb(urb, GFP_ATOMIC);
- if (unlikely(err))
- goto failed;
- else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
+ if (unlikely(err)) {
+ can_free_echo_skb(netdev, context->echo_index);
+
+ usb_unanchor_urb(urb);
+ usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
+
+ atomic_dec(&priv->active_tx_urbs);
+
+ if (err == -ENODEV)
+ netif_device_detach(netdev);
+ else
+ netdev_warn(netdev, "failed tx_urb %d\n", err);
+ stats->tx_dropped++;
+ } else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
/* Slow down tx path */
netif_stop_queue(netdev);

@@ -691,19 +702,6 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,

return NETDEV_TX_BUSY;

-failed:
- can_free_echo_skb(netdev, context->echo_index);
-
- usb_unanchor_urb(urb);
- usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
-
- atomic_dec(&priv->active_tx_urbs);
-
- if (err == -ENODEV)
- netif_device_detach(netdev);
- else
- netdev_warn(netdev, "failed tx_urb %d\n", err);
-
nomembuf:
usb_free_urb(urb);

--
2.17.1