From dd7054c333f63ec984c806d64018a1a5e31af4c6 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 3 Mar 2022 16:00:17 -0500 Subject: [PATCH] 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: 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: Reported-and-tested-by: syzbot+a48e3d1a875240cab5de@syzkaller.appspotmail.com Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/YiEsYTPEE6lOCOA5@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/usbtmc.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index 73f419adce610..4bb6d304eb4b2 100644 --- 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) -- 2.39.5