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From:   Zheyu Ma <zheyuma97@gmail.com>
To:     eli.billauer@gmail.com, arnd@arndb.de, gregkh@linuxfoundation.org
Cc:     linux-kernel@vger.kernel.org, Zheyu Ma <zheyuma97@gmail.com>
Subject: [PATCH v3] char: xillybus: Check endpoint type at probe time
Date:   Sun, 29 May 2022 14:58:39 +0800
Message-Id: <20220529065839.3817434-1-zheyuma97@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The driver submits bulk urb without checking the endpoint type is
actually bulk.

[    3.108690] usb 1-1: BOGUS urb xfer, pipe 3 != type 1
[    3.108983] WARNING: CPU: 0 PID: 211 at drivers/usb/core/urb.c:503 usb_submit_urb+0xcd9/0x18b0
[    3.110976] RIP: 0010:usb_submit_urb+0xcd9/0x18b0
[    3.115318] Call Trace:
[    3.115452]  <TASK>
[    3.115570]  try_queue_bulk_in+0x43c/0x6e0 [xillyusb]
[    3.115838]  xillyusb_probe+0x488/0x1230 [xillyusb]

Add a check at probe time to fix the bug.

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
Changes in v3:
    - Check the endpoint type more earlier
Changes in v2:
    - Check the endpoint type at probe time
---
 drivers/char/xillybus/xillyusb.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/char/xillybus/xillyusb.c b/drivers/char/xillybus/xillyusb.c
index dc3551796e5e..4ed19a2a04e3 100644
--- a/drivers/char/xillybus/xillyusb.c
+++ b/drivers/char/xillybus/xillyusb.c
@@ -167,6 +167,7 @@ struct xillyusb_dev {
 	struct device		*dev; /* For dev_err() and such */
 	struct kref		kref;
 	struct workqueue_struct	*workq;
+	struct usb_interface *intf;
 
 	int error;
 	spinlock_t error_lock; /* protect @error */
@@ -1891,6 +1892,17 @@ static const struct file_operations xillyusb_fops = {
 
 static int xillyusb_setup_base_eps(struct xillyusb_dev *xdev)
 {
+	int ret;
+	struct usb_endpoint_descriptor *in, *out;
+
+	ret = usb_find_common_endpoints(xdev->intf->cur_altsetting, &in, &out, NULL, NULL);
+	if (ret)
+		return ret;
+
+	if (in->bEndpointAddress != (IN_EP_NUM | USB_DIR_IN) ||
+		out->bEndpointAddress != (MSG_EP_NUM | USB_DIR_OUT))
+		return -EINVAL;
+
 	xdev->msg_ep = endpoint_alloc(xdev, MSG_EP_NUM | USB_DIR_OUT,
 				      bulk_out_work, 1, 2);
 	if (!xdev->msg_ep)
@@ -1916,6 +1928,21 @@ static int xillyusb_setup_base_eps(struct xillyusb_dev *xdev)
 	return -ENOMEM;
 }
 
+static int xillyusb_check_endpoint(struct xillyusb_dev *xdev, u8 addr)
+{
+	int i;
+	struct usb_host_interface *if_desc = xdev->intf->altsetting;
+
+	for (i = 0; i < if_desc->desc.bNumEndpoints; i++) {
+		struct usb_endpoint_descriptor *ep = &if_desc->endpoint[i].desc;
+
+		if (ep->bEndpointAddress == addr && usb_endpoint_is_bulk_out(ep))
+			return 0;
+	}
+
+	return -EINVAL;
+}
+
 static int setup_channels(struct xillyusb_dev *xdev,
 			  __le16 *chandesc,
 			  int num_channels)
@@ -1962,6 +1989,10 @@ static int setup_channels(struct xillyusb_dev *xdev,
 			chan->out_log2_element_size = out_desc & 0x0f;
 			chan->out_log2_fifo_size =
 				((out_desc >> 8) & 0x1f) + 16;
+			if (xillyusb_check_endpoint(xdev, (i+2) | USB_DIR_OUT)) {
+				kfree(xdev->channels);
+				return -EINVAL;
+			}
 		}
 	}
 
@@ -2125,6 +2156,7 @@ static int xillyusb_probe(struct usb_interface *interface,
 	mutex_init(&xdev->process_in_mutex);
 	mutex_init(&xdev->msg_mutex);
 
+	xdev->intf = interface;
 	xdev->udev = usb_get_dev(interface_to_usbdev(interface));
 	xdev->dev = &interface->dev;
 	xdev->error = 0;
-- 
2.25.1