Re: [syzbot] WARNING in hid_submit_ctrl/usb_submit_urb
From: Oleksandr Natalenko <hidden>
Date: 2021-08-30 19:23:01
Also in:
linux-input, lkml
Hello. On čtvrtek 19. srpna 2021 21:53:00 CEST Alan Stern wrote:
quoted hunk ↗ jump to hunk
On Thu, Aug 19, 2021 at 10:35:11AM -0700, syzbot wrote:quoted
Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: WARNING in hid_submit_ctrl/usb_submit_urb cm6533_jd 0003:0D8C:0022.0001: submit_ctrl: maxpacket 64 len 0 padlen 0 ------------[ cut here ]------------ usb 1-1: BOGUS control dir, pipe 80000280 doesn't match bRequestType a1Ah. The padding code doesn't add anything if the length is already a multiple of the maxpacket value, and of course 0 is such a multiple. The following simplified variant of Michal's patch should fix the problem. Alan Stern #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 794c7931a242 Index: usb-devel/drivers/hid/usbhid/hid-core.c ===================================================================--- usb-devel.orig/drivers/hid/usbhid/hid-core.c +++ usb-devel/drivers/hid/usbhid/hid-core.c@@ -377,27 +377,23 @@ static int hid_submit_ctrl(struct hid_de len = hid_report_len(report); if (dir == USB_DIR_OUT) { usbhid->urbctrl->pipe = usb_sndctrlpipe(hid_to_usb_dev(hid),
0);
- usbhid->urbctrl->transfer_buffer_length = len;
if (raw_report) {
memcpy(usbhid->ctrlbuf, raw_report, len);
kfree(raw_report);
usbhid->ctrl[usbhid->ctrltail].raw_report = NULL;
}
} else {
- int maxpacket, padlen;
+ int maxpacket;
usbhid->urbctrl->pipe = usb_rcvctrlpipe(hid_to_usb_dev(hid), 0);
maxpacket = usb_maxpacket(hid_to_usb_dev(hid),
usbhid->urbctrl->pipe, 0);
- if (maxpacket > 0) {
- padlen = DIV_ROUND_UP(len, maxpacket);
- padlen *= maxpacket;
- if (padlen > usbhid->bufsize)
- padlen = usbhid->bufsize;
- } else
- padlen = 0;
- usbhid->urbctrl->transfer_buffer_length = padlen;
+ len += (len == 0); /* Don't allow 0-length reports */
+ len = round_up(len, maxpacket);
+ if (len > usbhid->bufsize)
+ len = usbhid->bufsize;
}
+ usbhid->urbctrl->transfer_buffer_length = len;
usbhid->urbctrl->dev = hid_to_usb_dev(hid);
usbhid->cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE | dir;I've tried both Michal's patch as well as this one, and both work for me, hence feel free to add this: Tested-by: Oleksandr Natalenko <redacted> once the fix is submitted. Thanks! -- Oleksandr Natalenko (post-factum)