Patch "cdc-acm: fix NULL pointer reference" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

cdc-acm: fix NULL pointer reference

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:
cdc-acm-fix-null-pointer-reference.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 <[email protected]> know about it.

From: Oliver Neukum <[email protected]>
Date: Thu, 7 Jan 2016 11:01:00 +0100
Subject: cdc-acm: fix NULL pointer reference

From: Oliver Neukum <[email protected]>

commit 29c6dd591bbd592472247441de9fa694acdabae8 upstream.

The union descriptor must be checked. Its usage was conditional before the parser was introduced. This is important, because many RNDIS device, which also use the common parser, have bogus extra descriptors.

---
 drivers/net/usb/cdc_ether.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

@@ -160,6 +160,12 @@ int usbnet_generic_cdc_bind(struct usbne
 	info->u = header.usb_cdc_union_desc;
 	info->header = header.usb_cdc_header_desc;
 	info->ether = header.usb_cdc_ether_desc;
+	if (!info->u) {
+		if (rndis)
+			goto skip;
+		else /* in that case a quirk is mandatory */
+			goto bad_desc;
+	}
 	/* we need a master/control interface (what we're
 	 * probed with) and a slave/data interface; union
 	 * descriptors sort this all out.

@@ -256,7 +262,7 @@ skip:
 			goto bad_desc;
 		}
 
-	} else if (!info->header || !info->u || (!rndis && !info->ether)) {
+	} else if (!info->header || (!rndis && !info->ether)) {
 		dev_dbg(&intf->dev, "missing cdc %s%s%sdescriptor\n",
 			info->header ? "" : "header ",
 			info->u ? "" : "union ",

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/cdc-acm-fix-null-pointer-reference.patch queue-4.4/usbnet-cleanup-after-bind-in-probe.patch