media: flexcop-usb: fix endpoint type check

commit 763679f0eeff0185fc431498849bbc1c24460875 upstream.

Commit d725d20e81c2 ("media: flexcop-usb: sanity checking of endpoint
type") tried to add an endpoint type sanity check for the single
isochronous endpoint but instead broke the driver by checking the wrong
descriptor or random data beyond the last endpoint descriptor.

Make sure to check the right endpoint descriptor.

Fixes: d725d20e81c2 ("media: flexcop-usb: sanity checking of endpoint type")
Cc: Oliver Neukum <oneukum@suse.com>
Cc: stable@vger.kernel.org	# 5.9
Reported-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20220822151027.27026-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/usb/b2c2/flexcop-usb.c b/drivers/media/usb/b2c2/flexcop-usb.c
index bfeb92d93de394311a6c03ea551cbccdc7513ec1..8ab1be03e7319a5442b7e295145fcaf456ac06ce 100644 (file)
--- a/drivers/media/usb/b2c2/flexcop-usb.c
+++ b/drivers/media/usb/b2c2/flexcop-usb.c
@@ -511,7 +511,7 @@ static int flexcop_usb_init(struct flexcop_usb *fc_usb)
 
        if (fc_usb->uintf->cur_altsetting->desc.bNumEndpoints < 1)
                return -ENODEV;
-       if (!usb_endpoint_is_isoc_in(&fc_usb->uintf->cur_altsetting->endpoint[1].desc))
+       if (!usb_endpoint_is_isoc_in(&fc_usb->uintf->cur_altsetting->endpoint[0].desc))
                return -ENODEV;
 
        switch (fc_usb->udev->speed) {