[PATCH 5.6 08/23] media: flexcop-usb: fix endpoint sanity check - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Oliver Neukum <oneukum@suse.com>,
	Johan Hovold <johan@kernel.org>, Sean Young <sean@mess.org>,
	Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Subject: [PATCH 5.6 08/23] media: flexcop-usb: fix endpoint sanity check
Date: Tue, 31 Mar 2020 10:59:20 +0200	[thread overview]
Message-ID: <20200331085311.616322806@linuxfoundation.org> (raw)
In-Reply-To: <20200331085308.098696461@linuxfoundation.org>

From: Johan Hovold <johan@kernel.org>

commit bca243b1ce0e46be26f7c63b5591dfbb41f558e5 upstream.

commit 1b976fc6d684 ("media: b2c2-flexcop-usb: add sanity checking") added
an endpoint sanity check to address a NULL-pointer dereference on probe.
Unfortunately the check was done on the current altsetting which was later
changed.

Fix this by moving the sanity check to after the altsetting is changed.

Fixes: 1b976fc6d684 ("media: b2c2-flexcop-usb: add sanity checking")
Cc: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/media/usb/b2c2/flexcop-usb.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/media/usb/b2c2/flexcop-usb.c
+++ b/drivers/media/usb/b2c2/flexcop-usb.c
@@ -511,6 +511,9 @@ static int flexcop_usb_init(struct flexc
 		return ret;
 	}
 
+	if (fc_usb->uintf->cur_altsetting->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	switch (fc_usb->udev->speed) {
 	case USB_SPEED_LOW:
 		err("cannot handle USB speed because it is too slow.");
@@ -544,9 +547,6 @@ static int flexcop_usb_probe(struct usb_
 	struct flexcop_device *fc = NULL;
 	int ret;
 
-	if (intf->cur_altsetting->desc.bNumEndpoints < 1)
-		return -ENODEV;
-
 	if ((fc = flexcop_device_kmalloc(sizeof(struct flexcop_usb))) == NULL) {
 		err("out of memory\n");
 		return -ENOMEM;


