usb: usbtmc: Fix bug in pipe direction for control transfers

The syzbot fuzzer reported a minor bug in the usbtmc driver:

usb 5-1: BOGUS control dir, pipe 80001e80 doesn't match bRequestType 0
WARNING: CPU: 0 PID: 3813 at drivers/usb/core/urb.c:412
usb_submit_urb+0x13a5/0x1970 drivers/usb/core/urb.c:410
Modules linked in:
CPU: 0 PID: 3813 Comm: syz-executor122 Not tainted
5.17.0-rc5-syzkaller-00306-g2293be58d6a1 #0
...
Call Trace:
 <TASK>
 usb_start_wait_urb+0x113/0x530 drivers/usb/core/message.c:58
 usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
 usb_control_msg+0x2a5/0x4b0 drivers/usb/core/message.c:153
 usbtmc_ioctl_request drivers/usb/class/usbtmc.c:1947 [inline]

The problem is that usbtmc_ioctl_request() uses usb_rcvctrlpipe() for
all of its transfers, whether they are in or out.  It's easy to fix.

CC: <stable@vger.kernel.org>
Reported-and-tested-by: syzbot+a48e3d1a875240cab5de@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YiEsYTPEE6lOCOA5@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 73f419adce610e9d633b7d2dc405322425cf89d4..4bb6d304eb4b21fe3049f44ca000826af2c40ff0 100644 (file)
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -1919,6 +1919,7 @@ static int usbtmc_ioctl_request(struct usbtmc_device_data *data,
        struct usbtmc_ctrlrequest request;
        u8 *buffer = NULL;
        int rv;
+       unsigned int is_in, pipe;
        unsigned long res;
 
        res = copy_from_user(&request, arg, sizeof(struct usbtmc_ctrlrequest));
@@ -1928,12 +1929,14 @@ static int usbtmc_ioctl_request(struct usbtmc_device_data *data,
        if (request.req.wLength > USBTMC_BUFSIZE)
                return -EMSGSIZE;
 
+       is_in = request.req.bRequestType & USB_DIR_IN;
+
        if (request.req.wLength) {
                buffer = kmalloc(request.req.wLength, GFP_KERNEL);
                if (!buffer)
                        return -ENOMEM;
 
-               if ((request.req.bRequestType & USB_DIR_IN) == 0) {
+               if (!is_in) {
                        /* Send control data to device */
                        res = copy_from_user(buffer, request.data,
                                             request.req.wLength);
@@ -1944,8 +1947,12 @@ static int usbtmc_ioctl_request(struct usbtmc_device_data *data,
                }
        }
 
+       if (is_in)
+               pipe = usb_rcvctrlpipe(data->usb_dev, 0);
+       else
+               pipe = usb_sndctrlpipe(data->usb_dev, 0);
        rv = usb_control_msg(data->usb_dev,
-                       usb_rcvctrlpipe(data->usb_dev, 0),
+                       pipe,
                        request.req.bRequest,
                        request.req.bRequestType,
                        request.req.wValue,
@@ -1957,7 +1964,7 @@ static int usbtmc_ioctl_request(struct usbtmc_device_data *data,
                goto exit;
        }
 
-       if (rv && (request.req.bRequestType & USB_DIR_IN)) {
+       if (rv && is_in) {
                /* Read control data from device */
                res = copy_to_user(request.data, buffer, rv);
                if (res)