From 6e1b3095ddd2aa5286c8219ee19ab77c0398b43f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bj=C3=B8rn=20Mork?= Date: Sun, 11 May 2014 10:47:13 +0200 Subject: [PATCH] net: cdc_mbim: reject IP packets on DSS VLANs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit DSS VLANs are pseudo network interfaces representing arbitrary data streams, and specifically not IP. Preventing spurious IP packets can sometimes be a hassle. The kernel will for example send an IPv6 Router Solicit when the interface is brought up unless the user has been careful enough to disable IPv6 first. Such packets forwared to a MBIM DSS session will look like spurious noise to the device, and can cause it to log an error or even malfunction. Drop all IP packets on the designated DSS VLANs to prevent such unwanted spurious transmissions. Cc: Greg Suarez Reported-by: Arnaud Desmier Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller --- drivers/net/usb/cdc_mbim.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c index 694a8790f695..80d27719ba38 100644 --- a/drivers/net/usb/cdc_mbim.c +++ b/drivers/net/usb/cdc_mbim.c @@ -237,6 +237,8 @@ static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb c[3] = tci; break; case 0x0100: /* VLAN ID 256 - 511 */ + if (is_ip) + goto error; sign = cpu_to_le32(USB_CDC_MBIM_NDP16_DSS_SIGN); c = (u8 *)&sign; c[3] = tci; -- 2.20.1