Commit 0a824efd authored by Alan Stern's avatar Alan Stern Committed by Jiri Kosina
Browse files

HID: usbhid: Fix warning caused by 0-length input reports



Syzbot found a warning caused by hid_submit_ctrl() submitting a
control request to transfer a 0-length input report:

	usb 1-1: BOGUS control dir, pipe 80000280 doesn't match bRequestType a1

(The warning message is a little difficult to understand.  It means
that the control request claims to be for an IN transfer but this
contradicts the USB spec, which requires 0-length control transfers
always to be in the OUT direction.)

Now, a zero-length report isn't good for anything and there's no
reason for a device to have one, but the fuzzer likes to pick out
these weird edge cases.  In the future, perhaps we will decide to
reject 0-length reports at probe time.  For now, the simplest approach
for avoiding these warnings is to pretend that the report actually has
length 1.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: syzbot+9b57a46bf1801ce2a2ca@syzkaller.appspotmail.com
Tested-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 5049307d
......@@ -389,6 +389,7 @@ static int hid_submit_ctrl(struct hid_device *hid)
maxpacket = usb_maxpacket(hid_to_usb_dev(hid),
usbhid->urbctrl->pipe, 0);
if (maxpacket > 0) {
len += (len == 0); /* Don't allow 0-length reports */
len = DIV_ROUND_UP(len, maxpacket);
len *= maxpacket;
if (len > usbhid->bufsize)
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment