[1/3] HID: usbhid: Fix flood of "control queue full" messages

Commit Message

Alan Stern Sept. 1, 2021, 4:35 p.m. UTC

From: Michal Kubecek <[e-mail]>

[patch description by Alan Stern]

Commit 7652dd2c5cb7 ("USB: core: Check buffer length matches wLength
for control transfers") causes control URB submissions to fail if the
transfer_buffer_length value disagrees with the setup packet's wLength
valuel.  Unfortunately, it turns out that the usbhid can trigger this
failure mode when it submits a control request for an input report: It
pads the transfer buffer size to a multiple of the maxpacket value but
does not increase wLength correspondingly.

These failures have caused problems for people using an APS UPC, in
the form of a flood of log messages resembling:

	hid-generic 0003:051D:0002.0002: control queue full

This patch fixes the problem by setting the wLength value equal to the
padded transfer_buffer_length value in hid_submit_ctrl().  As a nice
bonus, the code which stores the transfer_buffer_length value is now
shared between the two branches of an "if" statement, so it can be
de-duplicated.

Signed-off-by: Michal Kubecek <[e-mail]>
Signed-off-by: Alan Stern <[e-mail]>
Fixes: 7652dd2c5cb7 ("USB: core: Check buffer length matches wLength for control transfers")
Tested-by: Oleksandr Natalenko <[e-mail]>
Tested-by: Benjamin Tissoires <[e-mail]>
Acked-by: Benjamin Tissoires <[e-mail]>
Cc: [e-mail]

---

 drivers/hid/usbhid/hid-core.c |   15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

Comments

Jiri Kosina Sept. 1, 2021, 6:53 p.m. UTC | #1

On Wed, 1 Sep 2021, Alan Stern wrote:

> From: Michal Kubecek <[e-mail]>
> 
> [patch description by Alan Stern]
> 
> Commit 7652dd2c5cb7 ("USB: core: Check buffer length matches wLength
> for control transfers") causes control URB submissions to fail if the
> transfer_buffer_length value disagrees with the setup packet's wLength
> valuel.  Unfortunately, it turns out that the usbhid can trigger this
> failure mode when it submits a control request for an input report: It
> pads the transfer buffer size to a multiple of the maxpacket value but
> does not increase wLength correspondingly.
> 
> These failures have caused problems for people using an APS UPC, in
> the form of a flood of log messages resembling:
> 
> 	hid-generic 0003:051D:0002.0002: control queue full
> 
> This patch fixes the problem by setting the wLength value equal to the
> padded transfer_buffer_length value in hid_submit_ctrl().  As a nice
> bonus, the code which stores the transfer_buffer_length value is now
> shared between the two branches of an "if" statement, so it can be
> de-duplicated.
> 
> Signed-off-by: Michal Kubecek <[e-mail]>
> Signed-off-by: Alan Stern <[e-mail]>
> Fixes: 7652dd2c5cb7 ("USB: core: Check buffer length matches wLength for control transfers")
> Tested-by: Oleksandr Natalenko <[e-mail]>
> Tested-by: Benjamin Tissoires <[e-mail]>
> Acked-by: Benjamin Tissoires <[e-mail]>
> Cc: [e-mail]
> 

Thanks Alan, applied and I will be sending whole HID tree to Linus soon.

(BTW, something broke your threading, so 2/3 and 3/3 were not threaded 
together with 1/3).

Patch

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 +377,26 @@  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;
+			len = DIV_ROUND_UP(len, maxpacket);
+			len *= maxpacket;
+			if (len > usbhid->bufsize)
+				len = usbhid->bufsize;
 		} else
-			padlen = 0;
-		usbhid->urbctrl->transfer_buffer_length = padlen;
+			len = 0;
 	}
+	usbhid->urbctrl->transfer_buffer_length = len;
 	usbhid->urbctrl->dev = hid_to_usb_dev(hid);
 
 	usbhid->cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE | dir;