On Tue, 7 May 2019, Sasha Levin wrote:
> Hi,
>
> [This is an automated email]
>
> This commit has been processed because it contains a -stable tag.
> The stable tag indicates that it's relevant for the following trees: all
>
> The bot has tested the following trees: v5.0.13, v4.19.40, v4.14.116, v4.9.173, v4.4.179, v3.18.139.
>
> v5.0.13: Build OK!
> v4.19.40: Build OK!
> v4.14.116: Build OK!
> v4.9.173: Build OK!
> v4.4.179: Build OK!
> v3.18.139: Failed to apply! Possible dependencies:
> 0dd5f20cb35b ("[media] siano: get rid of sms_info()")
> 46b1e21fe50f ("[media] siano: add support for the media controller at USB driver")
> 5e022d1aa0be ("[media] siano: use pr_* print functions")
>
>
> How should we proceed with this patch?
>
> --
> Thanks,
> Sasha
Attached is a version of the patch which has been back-ported to
3.18.x.
Alan Stern
The syzkaller USB fuzzer found a general-protection-fault bug in the
smsusb part of the Siano DVB driver. The fault occurs during probe
because the driver assumes without checking that the device has both
IN and OUT endpoints and the IN endpoint is ep1.
By slightly rearranging the driver's initialization code, we can make
the appropriate checks early on and thus avoid the problem. If the
expected endpoints aren't present, the new code safely returns -ENODEV
from the probe routine.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-and-tested-by: syzbot+53f029db71c19a47325a@xxxxxxxxxxxxxxxxxxxxxxxxx
CC: <stable@xxxxxxxxxxxxxxx>
---
drivers/media/usb/siano/smsusb.c | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)
Index: usb-devel/drivers/media/usb/siano/smsusb.c
===================================================================
--- usb-devel.orig/drivers/media/usb/siano/smsusb.c
+++ usb-devel/drivers/media/usb/siano/smsusb.c
@@ -400,6 +400,7 @@ static int smsusb_init_device(struct usb
struct smsdevice_params_t params;
struct smsusb_device_t *dev;
int i, rc;
+ int in_maxp;
/* create device object */
dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL);
@@ -411,6 +412,24 @@ static int smsusb_init_device(struct usb
dev->udev = interface_to_usbdev(intf);
dev->state = SMSUSB_DISCONNECTED;
+ for (i = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
+ struct usb_endpoint_descriptor *desc =
+ &intf->cur_altsetting->endpoint[i].desc;
+
+ if (desc->bEndpointAddress & USB_DIR_IN) {
+ dev->in_ep = desc->bEndpointAddress;
+ in_maxp = usb_endpoint_maxp(desc);
+ } else {
+ dev->out_ep = desc->bEndpointAddress;
+ }
+ }
+
+ sms_info("in_ep = %02x, out_ep = %02x", dev->in_ep, dev->out_ep);
+ if (!dev->in_ep || !dev->out_ep) { /* Missing endpoints? */
+ smsusb_term_device(intf);
+ return -ENODEV;
+ }
+
params.device_type = sms_get_board(board_id)->type;
switch (params.device_type) {
@@ -425,24 +444,12 @@ static int smsusb_init_device(struct usb
/* fall-thru */
default:
dev->buffer_size = USB2_BUFFER_SIZE;
- dev->response_alignment =
- le16_to_cpu(dev->udev->ep_in[1]->desc.wMaxPacketSize) -
- sizeof(struct sms_msg_hdr);
+ dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr);
params.flags |= SMS_DEVICE_FAMILY2;
break;
}
- for (i = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) {
- if (intf->cur_altsetting->endpoint[i].desc. bEndpointAddress & USB_DIR_IN)
- dev->in_ep = intf->cur_altsetting->endpoint[i].desc.bEndpointAddress;
- else
- dev->out_ep = intf->cur_altsetting->endpoint[i].desc.bEndpointAddress;
- }
-
- sms_info("in_ep = %02x, out_ep = %02x",
- dev->in_ep, dev->out_ep);
-
params.device = &dev->udev->dev;
params.buffer_size = dev->buffer_size;
params.num_buffers = MAX_BUFFERS;
