From 29c6dd591bbd592472247441de9fa694acdabae8 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 7 Jan 2016 11:01:00 +0100 Subject: [PATCH] cdc-acm: fix NULL pointer reference 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. Signed-off-by: Oliver Neukum Tested-by: Vasily Galkin Signed-off-by: David S. Miller --- drivers/net/usb/cdc_ether.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c index 3da70bf..7cba2c3 100644 --- a/drivers/net/usb/cdc_ether.c +++ b/drivers/net/usb/cdc_ether.c @@ -160,6 +160,12 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) 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 ", -- 2.5.0