From e1f13c879a7c21bd207dc6242455e8e3a1e88b40 Mon Sep 17 00:00:00 2001 From: Anant Thazhemadam Date: Sat, 10 Oct 2020 13:59:32 +0530 Subject: [PATCH] staging: comedi: check validity of wMaxPacketSize of usb endpoints found While finding usb endpoints in vmk80xx_find_usb_endpoints(), check if wMaxPacketSize = 0 for the endpoints found. Some devices have isochronous endpoints that have wMaxPacketSize = 0 (as required by the USB-2 spec). However, since this doesn't apply here, wMaxPacketSize = 0 can be considered to be invalid. Reported-by: syzbot+009f546aa1370056b1c2@syzkaller.appspotmail.com Tested-by: syzbot+009f546aa1370056b1c2@syzkaller.appspotmail.com Signed-off-by: Anant Thazhemadam Cc: stable Link: https://lore.kernel.org/r/20201010082933.5417-1-anant.thazhemadam@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/vmk80xx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/staging/comedi/drivers/vmk80xx.c b/drivers/staging/comedi/drivers/vmk80xx.c index 65dc6c51037e..7956abcbae22 100644 --- a/drivers/staging/comedi/drivers/vmk80xx.c +++ b/drivers/staging/comedi/drivers/vmk80xx.c @@ -667,6 +667,9 @@ static int vmk80xx_find_usb_endpoints(struct comedi_device *dev) if (!devpriv->ep_rx || !devpriv->ep_tx) return -ENODEV; + if (!usb_endpoint_maxp(devpriv->ep_rx) || !usb_endpoint_maxp(devpriv->ep_tx)) + return -EINVAL; + return 0; }