media: flexcop-usb: fix endpoint type check

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 7835bb0..e012b21 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) {