This is a note to let you know that I've just added the patch titled
media: usb: siano: Fix general protection fault in smsusb
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 31e0456de5be379b10fea0fa94a681057114a96e Mon Sep 17 00:00:00 2001
From: Alan Stern stern@rowland.harvard.edu Date: Tue, 7 May 2019 12:39:47 -0400 Subject: media: usb: siano: Fix general protection fault in smsusb
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@rowland.harvard.edu Reported-and-tested-by: syzbot+53f029db71c19a47325a@syzkaller.appspotmail.com CC: stable@vger.kernel.org Reviewed-by: Johan Hovold johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/usb/siano/smsusb.c | 33 +++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c index 4fc03ec8a4f1..27ad14a3f831 100644 --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -400,6 +400,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) struct smsusb_device_t *dev; void *mdev; 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_interface *intf, int board_id) 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; + } + } + + pr_debug("in_ep = %02x, out_ep = %02x\n", 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_interface *intf, int board_id) /* 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; - } - - pr_debug("in_ep = %02x, out_ep = %02x\n", - dev->in_ep, dev->out_ep); - params.device = &dev->udev->dev; params.usb_device = dev->udev; params.buffer_size = dev->buffer_size;