Re: [PATCH] usb: gadget: midi2: remove default configfs groups on teardown

[Joshua Crofts]

On Mon, 3 Aug 2026 08:25:35 +0200
Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:

> On Mon, Aug 03, 2026 at 07:59:17AM +0200, Joshua Crofts wrote:
> > On Thu, 30 Jul 2026 at 15:58, Joshua Crofts <joshua.crofts1@xxxxxxxxx> wrote:  
> > >
> > > f_midi2_alloc_inst() creates default configfs child groups for the
> > > default endpoint and default block using configfs_add_default_group(),
> > > setting their internal refcount to 1.
> > >
> > > However, during function teardown in f_midi2_free_inst() or EP cleanup
> > > in f_midi2_ep_opts_release(), configfs_remove_default_groups() is
> > > never called, therefore never dropping the refcount and leaking struct
> > > f_midi2_ep_opts and f_midi2_block_opts.
> > >
> > > Add the missing configfs_remove_default_groups() in the afformentioned
> > > functions to free the structs properly.
> > >
> > > Fixes: 8b645922b223 ("usb: gadget: Add support for USB MIDI 2.0 function driver")
> > > Cc: <stable@xxxxxxxxxxxxxxx>
> > > Reported-by: syzbot+eaa106d192c9daf37f95@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Closes: https://syzkaller.appspot.com/bug?extid=eaa106d192c9daf37f95
> > > Tested-by: syzbot+eaa106d192c9daf37f95@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Signed-off-by: Joshua Crofts <joshua.crofts1@xxxxxxxxx>
> > > ---
> > > Aside from testing the fix locally with QEMU and the reproducer,
> > > syzbot also reports no issues after running `syz test`.
> > > ---  
> > 
> > Hi Greg,
> > 
> > Gentle ping on this patch.  
> 
> It's been 2 "business days" since you sent this.  What's the rush?  If
> you wish to see patches reviewed faster, please help out in reviewing
> other patches on the list.
> 
> And as this is really only a syzbot issue, the "severity" is low, right?
> 
> thanks,
> 
> greg k-h

Apologies, I let my impatience get the better of me :( won't happen again.

-- 
Kind regards,
Joshua Crofts