staging: fix USB altsetting bugs

We had quite a few drivers using the first alternate setting instead of the current one when doing descriptor sanity checks. This is mostly an issue on kernels with panic_on_warn set due to a WARN() in usb_submit_urb(), but since we've started backporting such fixes (e.g. as reported by syzbot), I've marked these for stable as well.

Johan

Johan Hovold (2):
staging: rtl8188eu: fix interface sanity check
staging: rtl8712: fix interface sanity check

 drivers/staging/rtl8188eu/os_dep/usb_intf.c | 2 +-
 drivers/staging/rtl8712/usb_intf.c          | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

2.24.0

Make sure to use the current alternate setting when verifying the interface descriptors to avoid binding to an invalid interface.

Failing to do so could cause the driver to misbehave or trigger a WARN() in usb_submit_urb() that kernels with panic_on_warn set would choke on.

---
 drivers/staging/rtl8188eu/os_dep/usb_intf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 4fac9dca798e..a7cac0719b8b 100644
@@ -70,7 +70,7 @@ static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
 	phost_conf = pusbd->actconfig;
 	pconf_desc = &phost_conf->desc;
 
-	phost_iface = &usb_intf->altsetting[0];
+	phost_iface = usb_intf->cur_altsetting;
 	piface_desc = &phost_iface->desc;
 
 	pdvobjpriv->NumInterfaces = pconf_desc->bNumInterfaces;

2.24.0

Make sure to use the current alternate setting when verifying the interface descriptors to avoid binding to an invalid interface.

Failing to do so could cause the driver to misbehave or trigger a WARN() in usb_submit_urb() that kernels with panic_on_warn set would choke on.

---
 drivers/staging/rtl8712/usb_intf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index ba1288297ee4..a87562f632a7 100644
@@ -247,7 +247,7 @@ static uint r8712_usb_dvobj_init(struct _adapter *padapter)
 
 	pdvobjpriv->padapter = padapter;
 	padapter->eeprom_address_size = 6;
-	phost_iface = &pintf->altsetting[0];
+	phost_iface = pintf->cur_altsetting;
 	piface_desc = &phost_iface->desc;
 	pdvobjpriv->nr_endpoint = piface_desc->bNumEndpoints;
 	if (pusbd->speed == USB_SPEED_HIGH) {

2.24.0