[PATCH 5.7 216/393] go7007: add sanity checking for endpoints

From: Greg Kroah-Hartman
Date: Mon Aug 17 2020 - 12:25:11 EST


From: Oliver Neukum <oneukum@xxxxxxxx>

[ Upstream commit 137641287eb40260783a4413847a0aef06023a6c ]

A malicious USB device may lack endpoints the driver assumes to exist
Accessing them leads to NULL pointer accesses. This patch introduces
sanity checking.

Reported-and-tested-by: syzbot+cabfa4b5b05ff6be4ef0@xxxxxxxxxxxxxxxxxxxxxxxxx

Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Fixes: 866b8695d67e8 ("Staging: add the go7007 video driver")
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/usb/go7007/go7007-usb.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/go7007/go7007-usb.c b/drivers/media/usb/go7007/go7007-usb.c
index f889c9d740cd1..dbf0455d5d50d 100644
--- a/drivers/media/usb/go7007/go7007-usb.c
+++ b/drivers/media/usb/go7007/go7007-usb.c
@@ -1132,6 +1132,10 @@ static int go7007_usb_probe(struct usb_interface *intf,
go->hpi_ops = &go7007_usb_onboard_hpi_ops;
go->hpi_context = usb;

+ 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 +1145,6 @@ 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 +1266,13 @@ 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 +1292,8 @@ 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)
--
2.25.1