From 3428fbcd6e6c0850b1a8b2a12082b7b2aabb3da3 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Tue, 10 Dec 2019 12:44:22 +0100
Subject: [PATCH] brcmfmac: fix interface sanity check
Git-commit: 3428fbcd6e6c0850b1a8b2a12082b7b2aabb3da3
Patch-mainline: v5.6-rc1
References: git-fixes

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.

Fixes: 71bb244ba2fd ("brcm80211: fmac: add USB support for bcm43235/6/8 chipsets")
Cc: stable <stable@vger.kernel.org>     # 3.4
Cc: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index 06f3c01f10b3..7cdfde9b3dea 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -1348,7 +1348,7 @@ brcmf_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 		goto fail;
 	}
 
-	desc = &intf->altsetting[0].desc;
+	desc = &intf->cur_altsetting->desc;
 	if ((desc->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
 	    (desc->bInterfaceSubClass != 2) ||
 	    (desc->bInterfaceProtocol != 0xff)) {
@@ -1361,7 +1361,7 @@ brcmf_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 
 	num_of_eps = desc->bNumEndpoints;
 	for (ep = 0; ep < num_of_eps; ep++) {
-		endpoint = &intf->altsetting[0].endpoint[ep].desc;
+		endpoint = &intf->cur_altsetting->endpoint[ep].desc;
 		endpoint_num = usb_endpoint_num(endpoint);
 		if (!usb_endpoint_xfer_bulk(endpoint))
 			continue;
-- 
2.16.4