On Wed, 1 Sep 2021, Alan Stern wrote:

From: Michal Kubecek <redacted>

[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 <redacted>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: 7652dd2c5cb7 ("USB: core: Check buffer length matches wLength for control transfers")
Tested-by: Oleksandr Natalenko <redacted>
Tested-by: Benjamin Tissoires <redacted>
Acked-by: Benjamin Tissoires <redacted>
Cc: stable@vger.kernel.org

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).

-- 
Jiri Kosina
SUSE Labs