From a006a724881bfb592db61ba17db1e217b9615cc4 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Wed, 22 Apr 2020 13:49:55 +0200 Subject: [PATCH] go7007: add only insanity checking A malicious USB device may lack endpoints the driver assumes to exist Accessing them leads to NULL pointer accesses. This patch introduces sanity checking. Signed-off-by: Oliver Neukum Fixes: 866b8695d67e8 ("Staging: add the go7007 video driver") --- drivers/media/usb/go7007/go7007-usb.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/go7007/go7007-usb.c b/drivers/media/usb/go7007/go7007-usb.c index f889c9d740cd..a45af149cadc 100644 --- a/drivers/media/usb/go7007/go7007-usb.c +++ b/drivers/media/usb/go7007/go7007-usb.c @@ -1132,6 +1132,20 @@ static int go7007_usb_probe(struct usb_interface *intf, go->hpi_ops = &go7007_usb_onboard_hpi_ops; go->hpi_context = usb; + if (!usb->usbdev) { + printk(KERN_ERR"It is full of stars!\n"); + BUG(); + } + + if (!usb->usbdev->ep_in) { + printk(KERN_ERR"It is also full of stars!\n"); + BUG(); + } + + ep = usb->usbdev->ep_in[4]; + if (!ep) + return -ENODEV; + /* Allocate the URB and buffer for receiving incoming interrupts */ usb->intr_urb = usb_alloc_urb(0, GFP_KERNEL); if (usb->intr_urb == NULL) @@ -1141,7 +1155,6 @@ static int go7007_usb_probe(struct usb_interface *intf, if (usb->intr_urb->transfer_buffer == NULL) goto allocfail; - ep = usb->usbdev->ep_in[4]; if (usb_endpoint_type(&ep->desc) == USB_ENDPOINT_XFER_BULK) usb_fill_bulk_urb(usb->intr_urb, usb->usbdev, usb_rcvbulkpipe(usb->usbdev, 4), @@ -1263,9 +1276,13 @@ static int go7007_usb_probe(struct usb_interface *intf, /* Allocate the URBs and buffers for receiving the video stream */ if (board->flags & GO7007_USB_EZUSB) { + if (!usb->usbdev->ep_in[6]) + goto allocfail; v_urb_len = 1024; video_pipe = usb_rcvbulkpipe(usb->usbdev, 6); } else { + if (!usb->usbdev->ep_in[1]) + goto allocfail; v_urb_len = 512; video_pipe = usb_rcvbulkpipe(usb->usbdev, 1); } @@ -1285,6 +1302,8 @@ static int go7007_usb_probe(struct usb_interface *intf, /* Allocate the URBs and buffers for receiving the audio stream */ if ((board->flags & GO7007_USB_EZUSB) && (board->main_info.flags & GO7007_BOARD_HAS_AUDIO)) { + if (!usb->usbdev->ep_in[8]) + goto allocfail; for (i = 0; i < 8; ++i) { usb->audio_urbs[i] = usb_alloc_urb(0, GFP_KERNEL); if (usb->audio_urbs[i] == NULL) -- 2.16.4