Bug#655387: [PATCH net v2] cdc_ether: Ignore bogus union descriptor for RNDIS devices
Hi Iker,
David Miller wrote:
> From: Bjørn Mork <bjorn@mork.no>
> Date: Thu, 26 Apr 2012 14:35:10 +0200
>> The same comments as for v1 regarding testing applies. This is build
>> tested only. Should go through some functional testing before being
>> applied.
>
> Well? Is anyone gonna test this?
Looks like it's up to you, unless some firmware upgrade already
made the problem go away.
It works like this:
0. prerequisites:
apt-get install git build-essential
1. grab the kernel history, if you don't already have it:
git clone \
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
2. add point releases:
cd linux
git remote add stable \
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
git fetch stable
3. configure, build, test:
git checkout stable/linux-3.2.y
cp /boot/config-$(uname -r) .config; # current configuration
make localmodconfig; # optional: minimize configuration
scripts/config --disable DEBUG_INFO
make deb-pkg; # optionally with -j<num> for parallel build
dpkg -i ../<name of package>; # as root
reboot
... test test test ...
Hopefully it reproduces the problem. So:
4. try the patch (attached):
cd linux
git am -3sc /path/to/the/patch
make deb-pkg; # maybe with -j4
dpkg -i ../<name of package>; # as root
reboot
... test test test ...
If you get a chance to try it, please report the result to Dave by
replying-to-all to his message (i.e., not this one). If you have any
questions, please don't hesitate to ask.
Thanks and hope that helps,
Jonathan
From: Bjørn Mork <bjorn@mork.no>
Date: Thu, 26 Apr 2012 14:35:10 +0200
Subject: cdc_ether: Ignore bogus union descriptor for RNDIS devices
Some RNDIS devices include a bogus CDC Union descriptor pointing
to non-existing interfaces. The RNDIS code is already prepared
to handle devices without a CDC Union descriptor by hardwiring
the driver to use interfaces 0 and 1, which is correct for the
devices with the bogus descriptor as well. So we can reuse the
existing workaround.
Cc: Markus Kolb <linux-201011@tower-net.de>
Cc: Iker Salmón San Millán <shaola@esdebian.org>
Cc: Jonathan Nieder <jrnieder@gmail.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: 655387@bugs.debian.org
Cc: stable@vger.kernel.org
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
drivers/net/usb/cdc_ether.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 4fd41443a9b0..eac4886afc36 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -83,6 +83,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
struct cdc_state *info = (void *) &dev->data;
int status;
int rndis;
+ bool android_rndis_quirk = false;
struct usb_driver *driver = driver_of(intf);
struct usb_cdc_mdlm_desc *desc = NULL;
struct usb_cdc_mdlm_detail_desc *detail = NULL;
@@ -195,6 +196,11 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
info->control,
info->u->bSlaveInterface0,
info->data);
+ /* fall back to hard-wiring for RNDIS */
+ if (rndis) {
+ android_rndis_quirk = true;
+ goto next_desc;
+ }
goto bad_desc;
}
if (info->control != intf) {
@@ -271,11 +277,15 @@ next_desc:
/* Microsoft ActiveSync based and some regular RNDIS devices lack the
* CDC descriptors, so we'll hard-wire the interfaces and not check
* for descriptors.
+ *
+ * Some Android RNDIS devices have a CDC Union descriptor pointing
+ * to non-existing interfaces. Ignore that and attempt the same
+ * hard-wired 0 and 1 interfaces.
*/
- if (rndis && !info->u) {
+ if (rndis && (!info->u || android_rndis_quirk)) {
info->control = usb_ifnum_to_if(dev->udev, 0);
info->data = usb_ifnum_to_if(dev->udev, 1);
- if (!info->control || !info->data) {
+ if (!info->control || !info->data || info->control != intf) {
dev_dbg(&intf->dev,
"rndis: master #0/%p slave #1/%p\n",
info->control,
--
1.7.10.1
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