From: Bjørn Mork Date: Fri, 1 Nov 2013 10:16:48 +0000 (+0100) Subject: net: cdc_ncm: only the control intf can be probed X-Git-Tag: firefly_0821_release~176^2~4992^2~79^2~13 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9fe0234c0bf8b3c412df0adc9ebbe6a1e95daf51;p=firefly-linux-kernel-4.4.55.git net: cdc_ncm: only the control intf can be probed The probed interface must be the master/control interface of the function. Make this explicit and simplify redundant tests. Cc: Alexey Orishko Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller --- diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 435fcc75d706..5aa3e60851d0 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -394,6 +394,9 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_ /* store ctx pointer in device data field */ dev->data[0] = (unsigned long)ctx; + /* only the control interface can be successfully probed */ + ctx->control = intf; + /* get some pointers */ driver = driver_of(intf); buf = intf->cur_altsetting->extra; @@ -411,9 +414,10 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_ break; union_desc = (const struct usb_cdc_union_desc *)buf; - - ctx->control = usb_ifnum_to_if(dev->udev, - union_desc->bMasterInterface0); + /* the master must be the interface we are probing */ + if (intf->cur_altsetting->desc.bInterfaceNumber != + union_desc->bMasterInterface0) + goto error; ctx->data = usb_ifnum_to_if(dev->udev, union_desc->bSlaveInterface0); break; @@ -459,14 +463,12 @@ advance: /* some buggy devices have an IAD but no CDC Union */ if (!union_desc && intf->intf_assoc && intf->intf_assoc->bInterfaceCount == 2) { - ctx->control = intf; ctx->data = usb_ifnum_to_if(dev->udev, intf->cur_altsetting->desc.bInterfaceNumber + 1); dev_dbg(&intf->dev, "CDC Union missing - got slave from IAD\n"); } /* check if we got everything */ - if ((ctx->control == NULL) || (ctx->data == NULL) || - ((!ctx->mbim_desc) && ((ctx->ether_desc == NULL) || (ctx->control != intf)))) + if (!ctx->data || (!ctx->mbim_desc && !ctx->ether_desc)) goto error; /* claim data interface, if different from control */