Re: FAILED: patch "[PATCH] USB: gadget: f_hid: fix deadlock in f_hidg_write()" failed to apply to 4.9-stable tree

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Sat, 2019-03-30 at 21:23 +0100, Greg KH wrote:
> On Sat, Mar 30, 2019 at 01:06:23PM -0700, James Bottomley wrote:
> > On Sat, 2019-03-30 at 20:57 +0100, gregkh@linuxfoundation.org
> > wrote:
> > > The patch below does not apply to the 4.9-stable tree.
> > > If someone wants it applied there, or to any other stable or
> > > longterm
> > > tree, then please email the backport, including the original git
> > > commit id to <stable@vger.kernel.org>.
> > 
> > [...]
> > 
> > > Cc: stable@vger.kernel.org # 4.11+
> > > Fixes: 749494b6bdbb ("usb: gadget: f_hid: fix: Move IN request
> > > allocation to set_alt()")
> > 
> > The cc: stable specifies 4.11+ because the commit it fixes went in
> > in
> > the 4.11 merge window.  Is there something incorrect with the
> > tagging
> > that makes you think it should apply to 4.9?
> 
> Commit 749494b6bdbb originally showed up in 4.11, but it was then
> backported to 4.10.2 and 4.9.90.  That is why I tried to apply it to
> 4.9.y and when it did not work, sent out the rejection notice.

Turns out there's a missing patch:

commit 25cd9721c2b16ee0d775e36ec3af31f392003f80
Author: Krzysztof Opasiak <k.opasiak@samsung.com>
Date:   Tue Jan 31 18:12:31 2017 +0100

    usb: gadget: f_hid: fix: Don't access hidg->req without spinlock
held


It changes one of the match lines from

	status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);

to

	status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);

which is why you get the rejection.

James