Re: [PATCH AUTOSEL 4.19 095/100] USB: usb-skeleton: fix use-after-free after driver unbind

[Johan Hovold]

On Tue, Oct 29, 2019 at 10:43:21AM +0100, Greg Kroah-Hartman wrote:
> On Tue, Oct 29, 2019 at 05:04:35AM -0400, Sasha Levin wrote:
> > On Fri, Oct 18, 2019 at 06:22:05PM -0400, Greg Kroah-Hartman wrote:
> > > On Fri, Oct 18, 2019 at 06:05:20PM -0400, Sasha Levin wrote:
> > > > From: Johan Hovold <johan@xxxxxxxxxx>
> > > > 
> > > > [ Upstream commit 6353001852776e7eeaab4da78922d4c6f2b076af ]
> > > > 
> > > > The driver failed to stop its read URB on disconnect, something which
> > > > could lead to a use-after-free in the completion handler after driver
> > > > unbind in case the character device has been closed.
> > > > 
> > > > Fixes: e7389cc9a7ff ("USB: skel_read really sucks royally")
> > > > Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> > > > Link: https://lore.kernel.org/r/20191009170944.30057-3-johan@xxxxxxxxxx
> > > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> > > > ---
> > > >  drivers/usb/usb-skeleton.c | 1 +
> > > >  1 file changed, 1 insertion(+)
> > > 
> > > This file does not even get built in the kernel tree, no need to
> > > backport anything for it :)
> > 
> > I'll drop it, but you're taking patches for this driver:
> > https://lore.kernel.org/patchwork/patch/1140673/ .
> 
> Ah yeah, I probably shouldn't have taken stable backports for that, my
> fault.

Note that this was all due to

	https://lkml.kernel.org/r/20190930161205.18803-2-johan@xxxxxxxxxx

which fixed a PM bug due to an API change that was backported to stable.

I considered it comparable to a documentation fix to make sure that the
template driver matched the new API, hence the stable tag.

Johan