diff mbox series

[net] net: hdlc_raw_eth: Clear the IFF_TX_SKB_SHARING flag after calling ether_setup

Message ID 20201020063420.187497-1-xie.he.0141@gmail.com (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series [net] net: hdlc_raw_eth: Clear the IFF_TX_SKB_SHARING flag after calling ether_setup | expand

Commit Message

Xie He Oct. 20, 2020, 6:34 a.m. UTC
This driver calls ether_setup to set up the network device.
The ether_setup function would add the IFF_TX_SKB_SHARING flag to the
device. This flag indicates that it is safe to transmit shared skbs to
the device.

However, this is not true. This driver may pad the frame (in eth_tx)
before transmission, so the skb may be modified.

Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
---
 drivers/net/wan/hdlc_raw_eth.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Jakub Kicinski Oct. 22, 2020, 1:01 a.m. UTC | #1
On Mon, 19 Oct 2020 23:34:20 -0700 Xie He wrote:
> This driver calls ether_setup to set up the network device.
> The ether_setup function would add the IFF_TX_SKB_SHARING flag to the
> device. This flag indicates that it is safe to transmit shared skbs to
> the device.
> 
> However, this is not true. This driver may pad the frame (in eth_tx)
> before transmission, so the skb may be modified.
> 
> Cc: Neil Horman <nhorman@tuxdriver.com>
> Cc: Krzysztof Halasa <khc@pm.waw.pl>
> Signed-off-by: Xie He <xie.he.0141@gmail.com>

Applied, thank you. 

In the future please try to provide a Fixes: tag.
Xie He Oct. 22, 2020, 1:20 a.m. UTC | #2
On Wed, Oct 21, 2020 at 6:02 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> Applied, thank you.
>
> In the future please try to provide a Fixes: tag.

OK. Thanks! I'll remember this in the future!
diff mbox series

Patch

diff --git a/drivers/net/wan/hdlc_raw_eth.c b/drivers/net/wan/hdlc_raw_eth.c
index 08e0a46501de..c70a518b8b47 100644
--- a/drivers/net/wan/hdlc_raw_eth.c
+++ b/drivers/net/wan/hdlc_raw_eth.c
@@ -99,6 +99,7 @@  static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
 		old_qlen = dev->tx_queue_len;
 		ether_setup(dev);
 		dev->tx_queue_len = old_qlen;
+		dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 		eth_hw_addr_random(dev);
 		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
 		netif_dormant_off(dev);